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Throwing Kinematics and Children’s Abilities in the
Imaginary Ball Situation
Peter S. Capucilli
Thesis completed in partial fulfillment
of the requirements of the
Honors Program in Psychological Sciences
Under the Direction of Professor John J. Rieser
Vanderbilt University
April, 2007
Approved
_____________________________
Date
_______________
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Dedication
I dedicate this thesis to my parents, my sister and of course Huckleberry. Without
their continued reassurance, encouragement, support, and love, this work would not have
been possible. Thank you for allowing me these years at a wonderful institution.
-P.S.C.
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Acknowledgements
I wish to thank the team of researchers associated with this study. Their guidance
and participation has been most appreciated. I would especially like to express my
gratitude to Gayathri Narasimham for her time and dedication to the project. I sincerely
appreciate Karen Rieser for providing participants for this study. Thank you to Dr. Craig
Smith for his constant advising and logistical expertise since day one. To Dr. Michael
Rose for his undying support of my work and for inspiring me throughout my
undergraduate career. To Dr. Sue Hespos for introducing me to the world of
developmental psychology and research. I would not have participated in this program
without the invaluable experience of working in your lab.
Finally, I would like to thank my major professor Dr. John J. Rieser. I thank John
for his wonderful mentorship and active participation in research, as well as his
confidence to allow me the freedom to think, discover and imagine. I also thank John for
his kind human spirit, as well as his respect and interest in my overall wellbeing. I believe
this to be a rare quality of such a well-regarded professor.
-P.S.C.
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ABSTRACT:
A preliminary study conducted by Rieser et al. (2005) found a discrepancy in the
technique three to five year old children use when throwing a tangible ball vs. pretending
to throw an imaginary ball at targets varying in distance. In the real situation, children
release with the appropriate technical motion expected for each distance. With a pretend
ball, children failed to vary the kinematics of their throws in ways that reflected the need
to throw to further and further away targets. This disparity is not observed in adults.
Observations were conducted under randomized distance trials where children threw
three throws at four distances. The current study examined if blocking for distance
(repetitive throwing trials at each distance) serves as a possible means to reduce young
children’s failure in the pretend condition. Results indicated that children’s success in the
imaginary situation correlated with increased age and blocking for distance.
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Throwing Kinematics and Children’s Abilities in the Imaginary Ball Situation
Is there a difference between the throwing strategies (defined in terms of the
number of swing points in their throws) children choose when throwing a ball towards a
target and throwing strategies selected when asked to throw a pretend ball at that same
target? What are the throwing abilities of a child vs. those of an adult? Past research has
expressed interest in the general tendencies of children to form misconceptions on
various issues related to the kinematics and techniques necessary to throw a ball
accurately. Such questions include children’s knowledge and the ability of a child to
explain his or her actions in a throwing technique as well as whether children have what
Krist (2005) refers to as “action knowledge,” or “controlled processes that organize and
postures and movements to serve some function” (Reed, 1982, as cited in Krist, 2003).
Research by Krist (2001) illustrated that while they are moving, young children are
unable to drop a ball at the correct release point to hit a target on the floor. Instead, they
continually released the ball too early. As a control of this observation, children were
asked to press a button when their hand moved over the target. Children’s success at this
task suggested that their failure in the release task was due to their lack of connection
between action and intention (Krist, 2001 as cited in Krist 2003). This research primarily
echoed the early works by Piaget (1976, 1978) in which he illustrated several instances
where children completed similar movement/action tasks successfully, yet were unable to
verbally explain the means of achieving success.
With the onset of the summer of 2005, an unusual observation was made by
Professor John Rieser of the Peabody College at Vanderbilt University, which spoke
directly to the past research mentioned above. When children were asked to throw a
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tangible ball at a series of targets, with ranging distances, the kinematics of their throws,
or throwing technique, and overall body movements mimicked those of an adult throwing
a ball. The kinematics of their throwing strategies, as measured by the degrees of freedom
in arm movement variation and the addition or subtraction of force, were accurate to the
distance and force needed to reach each target. However when children were asked to
pretend to throw a ball, that is an imaginary or pretend ball, at the same distances, they
did not account for the appropriate modifications necessary to project a ball accurately
and according to various distances of the targets. Instead, children, on the whole, utilized
the same techniques for each distance. This observation implies the cognitive inability of
a child to imaginatively comprehend the alterations necessary to pretend to throw a ball at
targets of varied distances. That is, whereas a child is able to physically change his or her
throwing technique in order to reach a series of target distances, children seem unable to
comprehend that a change in arm motion is necessary if a tangible ball is not used. This
key occurrence would become the foregrounds of research aiming to decipher as to why
and what specific factors cause children to display this failure in the pretend condition.
Based on these preliminary observations, the early stages of a full research
experiment by Rieser et al. were put into action. Work in the summer of 2005 gathered a
number of 3-5 year olds in a controlled experiment to definitively support the unofficial
observations explained above. At this young age, it was positively confirmed that
children do indeed show a discrepancy in the kinematics of their throws in the real vs.
pretend situation. Adult control participants did not display failure in the imaginary
situation as they successfully pretended to represent different throwing techniques for
different target distances. At such point it was still to be determined as to what specific
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age children discontinue this pattern of failure in pretend throwing. Future research
proposed to determine if 5-9 year olds illustrate these differences as well as 13-15 year
olds. Despite the fact that the research by Rieser et al. is currently in its early stages of
data collection and analysis, much significance in the results determined poses further
questions for additional research to be explored. Such questions include the specific age
at which children begin to succeed in the pretend condition, and the effect of the
alteration of a single factor in the eradication of children’s failure at this task.
What are the positive implications for research within developmental psychology
for children’s throwing abilities in the real and pretend conditions? The further
application of potential knowledge obtained might be broken down into both practical
and theoretical uses. While the theoretical implications might appear definite to the
observer, the practical implications are a bit more difficult to explicate. The first
theoretical application speaks to the issue of the domination of senses. Does the sense of
vision or touch dominate a child’s ability to internalize motion? What is happening
neurologically that accounts for a child’s inability to transfer knowledge from throwing a
real ball to throwing a ball in an imaginary situation? If we are able to narrow the
possibilities as to the source of this change in technique, we might apply this knowledge
to understanding a greater piece of the overall field of children’s developmental
psychology. Additionally, novel observations might answer unidentified queries
regarding the human senses and sensory influence as well as the potential of specific
stimulations or situations that bolster sensory override. As this test will explore the
possibility that blocking for distance (repetitive throwing trials at each distance) will
affect a child’s ability to internalize, learn and further map motions to a novel task, the
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results of the research might speak to the future methods for throwing training in children
and further methods that might be used to teach children throwing technique. Moreover,
the results might speak to specific techniques or training opportunities that relate to all
motion, including situation dealing with motor disabilities and dysfunction, as well as
rehabilitation and conditioning. Finally, the results of the research might speak to the
development of certain aspects of the developing child, most specifically in relation to the
development of a child’s imagination and stages of pretend play. The implications will
likely prove worthy as a notable piece of knowledge in the greater picture of human
development.
While the introductory work by Rieser et al. (2005) served as the major basis for
the design of this study, other former works have served to provide insight on the
proposed hypotheses and reasons as to why children exhibit a difference in throwing
kinematics. Much of the related research deals with the ecological end of development in
a child, while other research focuses on mechanical development. Research regarding the
development of pretense in children was also considered. Since the current study
proposed deals with a task relating to a variety of forces, we integrated the fields of
ecological, mechanical and psychological development in children to form original
hypotheses that might provide insight to the results observed in Rieser et al’s (2005)
preliminary study.
In Rider and Rieser, (1988) children were shown an object on one side of a room
split by a dividing wall. Children were then guided past the door entrance (on the same
side of the room) and around the divider wall. Children were asked to point to the
location of the toy, which was now located on the other side of the wall, hidden from the
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child’s view. Children had been led parallel to the toy, and were expected to point
through the wall; their position was the same as the toy, on the opposite side of the room.
However, children tended to point towards the entrance of the door they had passed,
illustrating their inability to recognize their own motion around the room and ultimate
direction from the toy. However, a second study, in which children entered a darkened
room, was conducted. As children could not see inside the room, they were able to feel
the location of the toy before being led around the wall. When children were
subsequently asked to point towards the direction of the toy, results indicated that
children were able to point towards the correct location of the toy. Thus, the results
indicated that children were more attentive to kinematics of body movement when they
were unable to see their location and must have been aware of the direction and
movement that their body had taken. The results of this work illustrate the possibility that
vision might alter a child’s ability to understand the kinematics of his or her body.
Conditt, Gandolfo, & Mussa-Ivaldi (1997) studied learning mechanisms of motor
adaptation of strategies to applied outside force and the implication regarding the learning
process by which people map these strategies to completing tasks. In a drawing and
reaching study, participants were asked to use joystick type of manipulation in order to
draw a series of figures. While they were using this manipulation, forces were applied to
the joystick and subjects needed to learn to anticipate and adapt to the forces so their
drawings were accurate. Through this study, experimenters measured the kinematics
participants used to succeed at the task as they altered their motions in relation to the
contradictory force. Two hypotheses were explored. The first hypothesis was that
learning occurred through a technique of mapping specific states and forces with arm
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positions necessary to complete the task at those states. The second hypothesis was that
adaptation to the task occurred through memorization of the sequence of forces
experienced throughout the specific task at specific points. Results indicated that a
person’s adaptation and success involved his or her ability to represent and act on the
structure of the task environment, so that the representation included specific physical
forces and dynamics needed to succeed. Thus, the pre-exposure to a specific revisited
state allowed participants to apply necessary arm techniques to complete the task
correctly. The presence of this adaptive learning speaks to the human ability to construct
internal representations of dynamics necessary to use during motor control changes to
one’s environment and further suggests that accomplishment of a specific task is ensured
by exposure to a task requiring related technique.
Research by Mah, Ferdinaldo, & Mussa-Ivaldi (2003) examined human ability to
learn mappings between object motion and physical force in the manipulation of free
moving, unstable and shifting object. Within the task, participants were asked to balance
a simulated inverted pendulum as external force and movement was applied. Subjects
were first trained in one arm posture and were subsequently asked to complete the task
again in a similar but varied arm location. Results indicated that participants did not
perform as successfully when asked to vary arm position for the motor task than in the
original situation. This suggested that an object model is established based on muscle
commands that are only useful in completing similar tasks. Thus, mapping techniques
among varied force manipulation tasks did not occur. While Mah et al. (2003) did not
indicate that mapping techniques were present in their specific study, they illustrated that
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motions learned on a single type of task would be mapped to a task requiring the same
requirements.
In keeping with a holistic approach to establishing an original hypothesis, we also
considered past research on the topic of pretend play and children’s abilities in an
imaginary situation. We considered research that dealt with the specific age groups in
question within our own study as well as the issue of children’s knowledge of pretend
physical action vs. cognitive understanding of pretend action. Thus, research by Angeline
Lillard (1998) on children’s cognitive knowledge of intended action in pretense was
evaluated. The study by Lillard (1998) examined children’s understanding of mental
representations and intensions in the pretend state. Children were shown a puppet that
displayed a certain action, and told about a characteristic of the puppet’s intentions that
were in direct conflict with its actions. In one case, children were shown a puppet named
Moe who was made to hop around while the experimenter explained that Moe was
hopping “just like a kangaroo.” Children were then told that Moe had no prior knowledge
of kangaroos and that Moe was not thinking about kangaroos as he hopped around in
front of the child. In order to evaluate a child’s understanding of the pretend state and the
necessary connections between cognitive awareness and physical action, children were
then asked if Moe was actually pretending to be a kangaroo. Results indicated that
children believed the puppet was indeed pretending, confirming that they judged the
puppets state of pretense on its actions rather than on its mental state. This of course
could not have been the case since Moe would not have been able to pretend to be a
kangaroo without former knowledge of such an entity. These inaccurate responses were
considered incomplete to a cognitively developed understanding of pretense, further
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illustrating that children of this age group are within the developing range of
understanding issues regarding pretense.
Several key points from the preceding literature shaped the design of the present
study. Results by Lillard (1998) suggest that children within the age range of 3-4 years
might be incapable of comprehending a connection between the cognitive understanding
of a physical actions and a correct display of that action, as they do not account for the
necessary cognitive understanding of a pretend task necessary to guide action in a
physical task. Thus, it might be the case that, despite alterations of a peripheral factor of
the test, results will be static based on children’s ecological cognitive development.
The results of Conditt et al. (1997) that indicate a person’s ability to learn and
internally represent the kinematics of their actions to refine and improve motions suggest
that participants of an accuracy-throwing test might also form an internal representation,
encompassing the proper techniques to reach varied target distances. It is our hope that
repetitive exposure to these techniques in blocked trials might aid in internalization and
translation of techniques to the similar task of pretending to throw a ball at varied target
distances. Equally, as in accordance to the results of Mah et al. (2003) in support of the
transfer and mapping of skills from one motor task to a related motor task, it is assumed
that a child throwing a real ball will internalize motions and utilize these skills in the
highly similar task of throwing an imaginary ball.
Much of the protocol of the current study is similar to the preliminary work by
Rieser et al. (2005), who completed randomized throwing trials across the throwdistances and repeated trials at each distance. They did this in order to reduce children’s
opportunities to attend to feedback in order to adjust their next throw. In the present
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study throw distance and repeated trials to the same target were both blocked. That is,
every subject threw first to the nearest target, then the next nearest, and so forth; and in
addition, three repeated throws to each target were blocked. In other words, each subject
was asked to look at the nearest target and then throw to it three times in a row, then to
look at the second nearest target and throw to it three times in a row, and so forth. If one
wants to find out how well children can throw as they enter the test situation, then one
might dispute this change in design; however, if one wants to create conditions that
optimize how well people throw, then this design makes sense. In addition, the present
study is aimed at understanding how children “throw” during the pretend condition; there
is no feedback and so blocking or distributing trials would not result in different
opportunities to learn from feedback. These participants will be given no feedback by
their initial throws and will only be able to base their judgments of distance on their own
observation of motion within their bodies. Further, although we concede that a blatant
and steady increase in distance might emphasize the necessity for changes in the
kinematics of their throwing actions across the trials. That is, a child must first parse a
transformation in distance, and act physically to alter his or her actions in accordance
with that specific reform. We argue that the factor of blocking for distance might simply
enlighten children to the specific task called for by the reserved instructions of the
experimenter.
Finally, the results by Rider and Rieser, (1988) indicating that children show
enhanced abilities to determine spatial distances, affirms that young children are aware of
the position of their body. This implies that during a throwing study, children might be
able to keep track or recognize the movement and degrees of freedom associated with the
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arm and body motion of throwing a ball. In summary, the connection between the
generalization of motor tasks, as well as a child’s intrinsic understanding of pretend
knowledge leads us to believe that adult-like motions in a throwing study with an
imaginary ball might be possible in children between the ages of 3-7, contradictory to the
results indicated by Rieser et al. (2005). Further, as children appear to be in the age range
of development of pretend play, we believe that alterations that allow children to attempt
to display adult-like abilities, such as adaptation and mapping strategies, might expedite a
child’s understanding and successful execution of a task. That is to say, if we establish
children in a situation where they might, naturally, by force, or by influence, utilize
techniques intrinsic to adults, we might allow them a better chance to succeed at these
tasks, with the appropriate techniques, that have only been utilized successfully by the
developed child. This calls attention to the discrepancies between a child’s physical
understanding of a task, based on setting alterations, and his or her cognitive
understanding of a task, also to be examined. It might be within the later findings that the
absolute validity of children’s complete knowledge of adult cognitive abilities can be
understood in relation to age range and developmental psychology.
While the various studies explored above concern the currently study, it is
important to note the limitations of the translation of this literature in forming our own
original hypothesis. Although the theories of technique mapping in tests speak to a
person’s mapping of throws in the real and imaginary situation, one must consider that
the past literature does not suggest that techniques observed above would have the same
effect in pretend throwing situations. Additionally, these results are based on participants
in the adult range only. Thus, the skills observed might not translate to child participants.
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Further, the results in regards to children’s inability to comprehend certain aspects of
pretend play might only hold legitimacy in regards to that single study. It is unclear at
this time if differences in comprehension occur as children perform a physical task. Thus,
while the research speaks to and suggests alterations to form our hypothesis, one must
recognized that differences in exact interpretation between past and the present studies.
As a follow-up to Rieser et al., (2005) the present study is aimed at two goals. The
first goal is to learn more about how children throw in the imaginary ball condition.
Children were asked to throw three times to each target with blocked distances. This
design was established to increase the chances that children might use the repeated trials
to learn how to adjust their throws. In addition, the condition in which participants began
was randomized such that half the subjects started throwing with a real ball, and the
others started throwing with a pretend ball. The second purpose of the study is to
determine the age when children begin reliably to adjust their throwing in the imaginary
ball task and if this success correlates with the explicit explanation for why different
types of throws are needed for the different distances. Various factors and potential
alterations of the preliminary work were considered in order to determine the most
effective means by which to extricate children’s failure previously observed in the
pretend condition. Several informal pilot tests were conducted bearing no official
statistical results. All observations and analyzed decisions were based on the subjective
opinions of the experimenters.
Initial pilot testing considered the factor of a simulated blind feedback response to
throws. This original hypothesis was based on Rider and Rieser (1988) and children’s
success at a task in a darkened room. Thus, we considered blindfolding children and
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providing verbal feedback to help them alter their throwing accuracy to the specific
target. We speculated that the input of vision interrupts a child’s ability to internalize
technique necessary to reach altered distances. A child’s failure in the imaginary task
then involved their lack of internalization of the kinematics of their throwing actions as
well as the distraction of paying attention to the sight of the target. We discarded this
design due to the complexity and potential inconsistency of experimenter verbal feedback
based on children’s varied performances.
We then considered the factor of touch as a means by which children would
succeed in the imaginary ball situation. We suggested that if children were able to keep
hold onto an object, without releasing it, during the pretend condition, then they would
utilize the correct throwing kinematics necessary to pretend to reach the appropriate
distances. This theory did not alter or improve the performance of child participants in
the imaginary situation on randomized trials. However, when distanced was blocked in
the pretend condition (initially as a means to expedite movement of the target between
distances), older children (5-7 year olds) did indeed began to alter pretend arm motions
for further distances. That is, the naive modification of Rieser et al’s (2005) preliminary
study illustrated unanticipated results that ultimately established the focus of the current
study. Thus, after consideration of the literature above in relation to the additional pilot
studies discussed, we came up with an original hypothesis regarding the added factor of
blocking for distance. Two novel studies were conducted to examine the possible
implication of this alteration.
Rather than testing under randomized distance trials, the study established four
distances at which children threw three consecutive throws at each distance in the real
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ball and pretend ball conditions. Children were randomized to begin in the real condition
or to begin in the pretend condition and completed twelve throws in each condition. All
trials began with the closest distance and increased accordingly through two medium
distances and an extremely long distance in order to pronounce the fact that distance was
continually changing. At the end of both conditions, children were verbally questions as
to which distance was the hardest and easiest to throw the ball to in both the real and
pretend conditions. Children were given no prior training and were simply instructed to
throw the ball into the bucket (target) before each trial distance. The age range for
children tested was also increased from Rieser et al’s (2005) preliminary study to better
understand at what age children begin to succeed at the imaginary ball task of the pretend
condition. Adults were tested in the same conditions in order to provide control results
for comparison between ages, however adult distances were augmented to account for
increased strength/ability and height of the older subject. In other words, we wanted
every subject to have some throw distances that were easy, and so we included the 1m
target distance, and others that were might be more difficult – for the children, the longest
distance was 10m (pilot testing indicated this was generally difficult for both age groups),
and for adults the longest target distances was 40m (again, pilot testing indicated this was
generally difficult for most adults).
Initial limitations of the study include the validity of blocking for distance. As
noted above, if we block for distance, we are allowing children multiple throws to each
distance, which may contribute to a child’s internalization of a specific arm movement to
a specific distance. If a child thus succeeds in the imaginary situation, is it because the
child is able to pretend, or is it rather because the child has internalized the technique due
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to extended practice? While results might indicate the success of a child in an imaginary
situation, we must examine holistically both physical and cognitive understanding of the
task before we can conclude that the child is capable of understanding and demonstrating
adult-like throwing capabilities in the same manner as an adult participant. If the child
were as capable as an adult of this type of pretend play, one would expect the child to
succeed on randomized trials as well. This is not the case. However, validity for potential
results in regards to blocking for distance nevertheless must be considered. Finally, as
this study is based upon a preliminary study, we are unable to solidly confirm the age at
which children tend to successfully complete the throwing task and illustrate adult-like
capabilities in order to construct completely informed hypotheses. Thus, it might be more
beneficial to determine the age at which children discern differences in pretend throwing,
and subsequently alter factors of the test to that specific age. Instead, this test seeks to
understand differences in performance over several age ranges. It is imperative to note
that this study is purely an additional preliminary study to that of Rieser et al. (2005) in
order to serve as the ground works for future research that will be discussed in relation to
the empirical and theoretical data collected upon completion and analysis.
In summary, we argue that the inability of a child to succeed at the task of
pretending to throw a ball at varied targets relies on the distraction of randomized
distance trials, as well as issues regarding the development of a child’s ability to pretend
and cognitively comprehend aspects of pretend play. We expect that if target distances
are presented to the child in a steady increasing order, those children of the correct
cognitively advanced age will demonstrate adult-like throwing capabilities in the
imaginary situation. Successful completion of this task would indicate that children do
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have the ability to physically understand the kinematics of throwing a ball even in the
imaginary setting if blocking for distance is established. However, cognitive
understanding must also be considered. We propose that the reason why children, when
asked to throw in randomized test trials, failed to change their throwing actions motions
in the imaginary ball situation was based on their inability to process necessary technique
after a single throw per distance. Further, we bear in mind that in the initial studies by
Rieser et al. (2005), children might not have either understand the task that was asked of
them or that the their development of cognitive understanding necessary to succeed in the
imaginary situation might have been premature to the task.
Due to children’s prior failures in the pretend condition under randomized
distance trials, and considering the study by Lillard (1998), we presume that 3-4 year olds
will succeed at the real ball task, yet continue to fail to display adult-like pretend
throwing capabilities in the pretend condition due to evidence of naiveté of pretend play
at this age. We hypothesize that blocking for distance will allow 5-7 year olds
additional/necessary feedback information and expect that trends of success at the task
will develop within this age range. Thus, we anticipate a mixed set of failures and
successes with 5-7 year olds as we consider this to be the age block in which children’s
development allows for the cognitive knowledge to correctly throw an imaginary ball at
varied distances. We also expect that a child’s verbal response as to the understanding of
the sensible changes associated with pretend throw will parallel the child’s success or
failure in the throwing task. In accordance with the preliminary study’s results, we
anticipate that participants who begin throwing in the real condition will display similar
results to those participants who begin in the imaginary condition as we are skeptical as
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to the possibility of a main effect dependent on beginning in opposite conditions. Finally,
we anticipate that all adult control participants will perform as expected (succeed in both
the real and pretend condition) and that adult’s verbal response will be consistent among
participants.
Methods
Participants
The participants were twenty children ranging from 3.9-7.11 years in age who
were recruited from local Nashville elementary schools and early childhood religious
schools. Four of the children were excluded from the study, because they were too old to
fit our age groups or because their tests were interrupted. The final sample included eight
children who ranged from 3.9-4.6 years of age and eight who ranged from 5.0 to 7.1
years of age. The children were all appeared to be typically developing and ranged in
socio-economic class and ethnicity of a random sampling of the general demographics of
the greater Nashville area. In addition eight Vanderbilt Undergraduate students
participated, ranging from 20.1-22.4 years of age. Equal numbers of males and females
were tested at each age bracket. Subjects were unpaid volunteers. Children provided
verbal assent and their parents/guardian provided written consent, and the adults provided
written consent.
Instruments
Objects utilized in the study included a series of standard sized multicolored
balloons that were filled with 5oz of sand with a diameter of 2 inches. All sand-filled
balloons were constructed and weighted appropriately for a standard throw of a child
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between the ages of 3 and 7. Additionally, a yard/inches rolling measuring tape was used
to mark and determine the distances at which the target would be placed. A ten-inch deep
“Sponge Bob Square Pants” cylinder bucket was used as the target and placed on the
measuring tape at the appropriate distance. A standard steel tape measure was used to
measure accuracy and distance of each throw. A standard video recorder was used to
record the participant’s throwing technique. On sight coding was conducted using the
“Distance/Accuracy Scale Sheet” (Appendix #7) in which each distance of the throw and
distance of accuracy was measured by the coder. The “Distance/Accuracy Scale Sheet”
and the “Pretend Throwing Kinematics Scoring Guide” (Appendix #8) were subsequently
used to code recorded tapes of children’s motions in order to determine the change in
degrees of freedom in a child’s throw in the pretend condition.
Design
The experiment in Study 1 involved three independent variables. One was the
Throw Distances; for the children, these were 1m, 3m, 5m and 10m; for the adults these
were 1m, 7m, 15m, and 40m. The other was Trial Number, since each subject was asked
to throw three times in a row to each target distance. Trial Distances and Trial were both
blocked; every subject started by throwing three times to the nearest target, then the nextnearest and so forth, as illustrated in Figure 1. The third variable was Throw Condition.
Half of the participants in each age group began the study in the real ball condition,
followed by the pretend condition, while the other half began the study with the pretend
condition followed by the real ball condition. That is, all participants either began
throwing a real ball or throwing an imaginary ball and no participant was tested twice.
Insert Figure 1 here
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The ages of the subjects were also varied. Children and adults were tested and
statistically analyzed within three distinct age blocks: young children (3-4 years), older
children (5-7 years) and adults (18+ years). These groups were further broken down into
sub-categories in consideration of the third independent variable. There were two major
types of dependent variables for the study. The first dependent variable was the actual
distance children and adults threw the sand-filled balloon in the Real Ball condition. In
order to compute actual distance we measured the straight distance between the
participant and the landing location of the ball as well as the accuracy of the ball’s
location in relation to the line of target, established by the rolling measuring tape. All
distances were recorded in meters to the nearest cm and the “c” measurement of distance
(this is illustrated in Figure 2) is the one that was entered into the statistical analyses.
Insert Figure 2 here
We considered this third measurement to be the actual distance of the
participant’s throw as it accounted for exact distance between the thrower and the object
as well as accuracy in relation to the target. The other dependent variable was the
assessment of how many throwing strategies a child used to accomplish a throw at a
different distance. We used The Pretend Throwing Kinematics Scoring Guide, (Appendix
#8) an original standardized coding scheme that established specific movements a person
might display in the alteration of a throw on varied distances. Based on the number of
techniques utilized between distance intervals, the coder assessed if the participant did or
did not display an informed strategy change, noting the intervals at which these changes
occurred. Additional dependent variables of the study were the differences in
performance among ages associated with the three blocks as well as differences regarding
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performance in participants beginning in the real condition and participants beginning in
the pretend condition.
Study 2 consisted of a short question and answer session that followed all of the
throwing tests. Eleven of the 16 children participated in this and all of the adults
participated. Questions were presented in the same order and all participants were asked
the same four questions regarding the difficulty and ease of pretend throws and real
throws to the targets. Some children who displayed increased verbal knowledge or adultlike behavior during pretend throwing tests were asked additional questions in order to
better understand if a direct correlation between a child’s displayed physical
understanding of the task and their cognitive ability to explain their actions in words
existed. These specific answers were not statistically coded among analysis of Study 2
data. The dependent variable of Study 2 was the child’s answers to each question while
the questions themselves served as the study’s independent variable.
Procedure
In Study 1, participants for each age group (n=8) were selected at random to begin
in either the real situation or the imaginary situation. Each participant was tested on
twelve throwing trials for each condition. Participants were presented with a starting
position in front of a rolling measuring tape stretched out on the ground. The measuring
tape was rolled out past the furthest distance considered. Children were given a few
minutes to familiarize themselves with the sand-filled balloons and began the test trials
after verbal consent was given to the experimenter. Before instructions were stated, the
bucket/target was placed directly on top of the rolling measuring tape at the initial and
closest distance considered. Participants were then verbally instructed to either throw the
24
ball in the bucket (Real/Pretend condition) or pretend to throw the ball in the bucket
(Pretend/Real condition). Participants were asked to repeat the throw two more times at
the first target. The target was then moved away from the participant to the next distance
at which time the throwing pattern was repeated. All participants received verbal praise
between each throw while distance of straight throw and accuracy were measured. Upon
completion in the first condition, participants were asked to complete the same twelve
throws in the opposite condition. No written coding for the imaginary situation was
recording during testing, however all imaginary and real ball test trials were recorded on
video camera and later coded by two experimenters for reliability.
Participants for each age group (n=8) in Study 2 consisted of children and adults
who had immediately completed all trials in Study 1. Upon completion of
throwing/pretending to throw, participants were asked four questions regarding throwing
with a real ball and throwing with an imaginary ball. Participants were first asked which
distance was the hardest to throw to with a ball in hand, followed by which distance was
the easiest to throw to with a ball in hand. Participants were then asked which distance
was the hardest distance to pretend to throw to, followed by which distance was the
easiest to pretend to throw to. Child participants who displayed knowledge of adult-like
pretend throwing capabilities were further questioned as to what actions were taken in the
imaginary situation to reach various targets and why these actions were taken.
Upon completion of data collection, the researcher compiled accuracy
measurements and coded for differences in technique by participants to determine if
alternate throwing techniques were utilized to reach different distances in both the real
and pretend conditions. Scores for all 24 participants were then compiled for statistical
25
testing. Compilation and differentiation between independent and dependent variables
were analyzed using SPSS and Microsoft Excel computer programs.
Results and Discussion
The first issue we addressed from Study 1 was children’s accuracy in their Real
condition throwing trials. To do this, we computed a two-way analysis of variance. The
factors accounted for were both considered within subjects. The first of these variables,
Target Distance, was the four levels of lengths a child was expected to throw the ball to.
The other factor was the three levels of the Trial Position established from the three
consecutive throws each child performed on the altered distances. The dependent variable
was the actual distances computed from accuracy length and projected distance, labeled
as Throw Distance. Initially, we wanted to find out whether Target Distance exerted a
significant effect on the Throw Distances, in order to understand whether subjects
increased the forces of their throws for the targets that were placed further away. In
addition, we sought to determine whether Trial Number exerted a significant effect on
Throw Distances, in order to understand whether subjects were able to learn across the
three repeated throws for a given target distances (or alternatively, to find out whether
subjects became bored across their repeated throws to a given target distance). The data
appear in Figures 3 through 5.
Insert Figures 3, 4 and 5 here
In summation of the reduction of data analysis, we submitted the Throw Distance
data to a Target Distance by Trial analysis of variance with repeated measures on both
variables. We conducted separate analyses for each age group because the adults and the
26
children were asked to throw at targets across different ranges of distance, so that the
longest distance would be challenging (but possible) for the subjects in each age group
(e.g. the children were asked to throw to targets ranging from 1m to 10m, and the adults
were asked to throw to targets ranging from 1m to 40m).
For the adults, the two-way analysis of variance showed a significant main effect of
distance, F(3,21)=59.90, p<.000, and the main effect of Trial was nonsignificant. Further,
the Target Distance by Trial interaction was nonsignificant. Follow-up t-tests were
conducted as planned comparisons of the median distances thrown by participants to
different targets. With adults, the differences between target 1 and target 2, target 2 and
target 3, and target 3 and target 4 were highly significant, paired t(7) = -13.3, -19.7, and 3.7 respectively, all p’s< .005. For the older children, the main effect of Target Distance
was significant, F(3, 21) =50.18, all p’s<.000, neither the main effect of Trial nor the
Target Distance by Trial interaction were significant. The differences between target 1
and target 2, target 2 and target 3, and target 3 and target 4 were again highly significant,
paired t(7) = -30.2, -9.6, and -4.5 respectively, all p’s < .005. Finally, for the younger
children, the main effect of Target Distance was significant, F(3,21) = 81.97, p<.000, and
the main effect of Trial was also significant, F(2, 22) = 7.3, p=.031. The differences
between target 1 and target 2, target 2 and target 3, and target 3 and target 4 were again
highly significant, paired t(7) = -19.4, -3.7, and -2.4 respectively, all p’s < .05. Follow-up
t-tests for the main effect of Trial showed that the younger children threw further on the
third trial than on the first trial.
Statistical analysis of Study 1 also included examination of the participants’
potential alterations of motion in relation to distance changes in both the Real and
27
Pretend conditions. We coded all videotapes for frequency of occurrence of a change in
technique between distances, which determined a physical adult-like understanding of the
task. Participants were coded using the Pretend Throwing Kinematics Scoring Guide
(Appendix #8) in order to determine alteration of body motion in appropriate conjunction
with a change in target distance. Data were coded and subsequently recoded for
reliability. (We have not included these data since we haven’t yet computed reliability
coeficients). All data were compiled in order to account for three specific questions in
relation to the original hypothesis. The figures in Table 1 display these results.
Insert Table 1 here
We first coded frequency of children in each age group to demonstrate a single correct
alteration in relation to distance in both conditions. We found that five of the eight 3-4
year olds showed adult-like capabilities in the pretend situation. Further, all eight of the
5-7 year olds illustrated adult-like capabilities in the pretend situation. We then
considered the exact interval between targets and determined the frequency at which each
age ranges showed alterations in technique on each interval. Frequencies for this data are
listed under (I-1, I-2, I-3) on Table 2. Finally, we calculated the total number of displayed
changes in technique observed in each participant. That is, each child had three intervals
in which they might have displayed changes in technique. As listed on Table 2, T∆ equals
the total (T) number of times a child accurately showed a change (∆) in technique over
the three intervals. Adult results accounted for complete success in the illustration of the
proper real/pretend techniques for all intervals considered over all participants.
These results contradict our original hypothesis that children in the 3-4 year range
would not succeed at illustrating adult-like capabilities in the pretend condition. We
28
assume the reason for this is that the throwing trials were blocked with respect to Target
Distance and Trial in the present experiment, whereas they were fully randomized in the
earlier one. Further, although we anticipated that only some 5-7 year olds would be able
to illustrate adult-like actions, these results show that all 5-7 year olds were successful in
the pretend condition. Adult results were in accordance with our original hypothesis. On
the whole, these results indicate that as age increases between 3-7 years, the kinematics
of the throw strategies change as well. Additionally, a single participant’s ability to
pretend correctly at a greater number of distance intervals increased with age. We chose
not to statistically account for differences in participants beginning in the real vs. pretend
condition at the discrepancy of the experimenter.
Verbal examination in Study 2 was coded by frequency of response. We
accounted for both children’s and adult’s responses to each of the four questions. It was
determined that 7 out of the 8 total children believed that the hardest target to throw to
with a real ball was the furthest distance. Also, 7 of the 8 children found the closest target
to be the easiest distance to throw to with a real ball. Next, we found that 6 of the 11 total
children found that the furthest distance was most difficult to pretend to throw to, while 7
of the 11 participants claimed that the closest distance was the easiest to pretend to. All
adults claimed that the hardest distance to throw the real ball to was the furthest distance,
while the easiest distance to throw to was the closest distance. In the pretend condition,
no distinct frequency was observed in adults for the hardest distance to pretend to throw
to. Answered varied among distances considerably. Finally, 6 of the 8 adults claimed that
the closest distance was the easiest distance to pretend to throw to. We found the results
of this study to be insignificant to the hypotheses above regarding the connection
29
between understanding the physical task of pretending to throw a ball and a cognitive
understanding of the task, as hardness of throw seems irrelevant to one’s understanding
of didactic technique to a physical task.
General Discussion
Within the discussion of the results observed, we considered our original
hypotheses in relation to the statistical data, and further accounted for limitations within
the study as well as future research that might be considered upon completion of this
study. Because our statistical findings were quite unpredictably different than our original
hypotheses, the first issues of the discussion pertain to reason why we might have
ineffectively accounted for the actions of children across both age ranges and adults. We
consider the likely effect of blocking for distance and reasons as to why we
underestimated the influence blocking for distance might have had on a child’s ability to
successfully complete the task. We then consider statistical results within Study 2 and
children’s verbal/cognitive response to actions in the real and throwing condition and
conclude with limitations and suggestions for continual alteration and additions to the
preliminary work begun in Rieser et al. (2005).
The first important analyzed within the statistical results speaks to the age at
which children begin to incorporate and account for adult-like capabilities in their
execution of the task presented in the pretend condition. We found this transition to occur
within the 3-4 year age block, while more consistently among 5-7 year old participants.
Yet, the question remains as to why this modification begins within these particular age
ranges. Further, why did we fail to account for the possibility that five of the eight
30
children in the 3-4 year age group would be able to complete the task using adult-like
pretend throwing techniques? We consider the practical explanations against the results
in support of our original proposal. It is often around the age of five that many children
begin to be exposed to throwing tasks on a regular basis. That is, children are exposed to
various organized situations where throwing a ball is a common occurrence. Such
exposures might including sports teams or even augmented practice of sports/throwing
games with friends and/or family. Further, as children begin to attend elementary school
around this age, it may be the case that children have been exposed to throwing tasks
within their schools, (in a physical education program for example) in which case,
success in the task would likely be due to prior increased practice. In retrospect, and in
consideration of the results, it seems plausible that 3-4 year children in an early daycare
program, such as the participants in the study, might also have been exposed to throwing
tasks on a regular basis. In any case, the potential for success due to previous practice
seems likely in the real ball situation, yet less likely as the reason to which children
succeeded in the pretend condition.
In regard to the field of developmental psychology, we consider related research
on children’s information processing abilities. According to DeMarie-Breblow & Miller,
(1988) children between the ages of 3 and 4 illustrate a different type of selective
attention in a learning task than children in the 7-8 year old range. When presented with
two categories of varied objects, and asked to remember objects in only a single category,
children in the 3-4 year range illustrated equal attention to objects in both categories,
while children in the 7-9 year old range were able to selectively remember a single set of
objects. These results might help us to understand the discrete occurrence of a significant
31
main effect on Trial by children in the youngest age group. It might be supported in light
of DeMarie-Breblow & Miller, (1988) that young and older children in this study utilized
two different strategies in their execution of the pretend condition task. The significant
main effect on Trial reflects that practice in the increased trials on each target allowed
children (3-4) to throw more accurately among the three trials. Because neither adults nor
older children illustrated a significant main effect on Trial, their success in the pretend
condition would not have been attributed to increased practice as a result of blocking for
distance. Thus, it might be considered that while children in the 3-4 year old age group
are successful at the pretend task when blocking for distance is considered, they might be
using a different technique than 5-7 year old children and adults also successful with
blocked distances. That is to say, children 3-4 are affected by the altered variable of
blocking for distance, as it allows them more practice to accurately throw and tone
technique, where as 5-7 year olds and adults are nor affected by blocking for distance in
this same fashion. This piece of evidence would support our original hypothesis because
it shows that children in the 5-7 age group use techniques similar to those of adults.
However, without prior knowledge of DeMarie-Breblow & Miller, (1988) we
were unable to account for varied task strategy displayed by young children, thus we
established a partially uninformed original hypothesis. Finally, we consider that the
influence of pilot testing on our original hypotheses might account for our
misunderstanding of the potential abilities of children in both age ranges. We
acknowledge that informal pilot testing likely would have been more valuable to our
hypothesis had trials been videotaped and coded as was done in the official study, rather
than analyzing children’s throws during testing conditions.
32
Still, the question remains as to why it is the case that participants begin to
demonstrate adult-like capabilities when blocking for distance was taken into
consideration as an independent variable. We suggested that increased practice might
have accounted for success in those children who did alter throwing strategies in the
younger age range (based on significant main effects on Trial). Why did blocking for
distance allow all children within the 5-7 year old age range to succeed in the pretend
task, when all children in the 3-5 year old age range failed under randomized distances in
Rieser et al. (2005)? Can we fully attribute blocking for distance to older children’s
complete success in the pretend situation, or might this claim be regarded as an
inaccurate blanket statement and bias in support of our original hypothesis? This
argument must be considered from both angles to produce a valid discussion.
We suggest that exposure to a steadily increasing distances emphasized the
occurrence of an altering target to the child and allowed them to better understand the
correlation between the continual augmentation of target and a necessary continual
change that had to accompany this growth. We note the infallible frequency of children in
the 5-7 year old range to alter the kinematics of their throws within the first interval of
1m to 3m. Further, we note that the 3 and 4 year olds altered the kinematics of their
throws on the final interval, 5m-10m, more frequently than on any other interval. We feel
that these two targets were the most obvious augmentations of intervals within the test.
This is simply because all children throwing to the target at one meter simply needed to
drop the ball in the bucket, whereas the change to 3 meters required a full, yet gentle,
throw towards the target. Secondly, the distance between the third target at 5 meters and
the last target at 10 meters was extreme in comparison to the other intervals because the
33
final distance was meant to force children to utilize total power and force to reach the
target. Thus, one value of blocking for distance that might have attributed to children’s
success was the presentation of two specific changes of targets that might have
consequently triggered children’s understanding of the need to alter arm motions in the
pretend situation, simply because the changes between within these intervals were so
obvious and exaggerated.
However, if this argument were completely sound, one would expect that children
would alter throws on randomized distance trials between the extremely close and
extremely far distances. This was not the case in the preliminary study. Future analysis of
statistical data as well as additional testing might examine if the specific change between
the 1 meter target and 3 meter target was essential to children’s further understanding and
physical alterations on subsequent intervals. In consideration of this, we cannot state
firmly that blocking for distance accounts as the single factor to influence children’s
success over all age groups, however, the high frequency and display of adult-like
kinematics from the simple alteration of this single factor suggests that it was at least
partly responsible for the change in results.
Further, the overwhelming success of children under blocked distance trials
establishes grounds for conducting further experiments with this incorporated variable.
As the participant number in each age group was in retrospect considered small, we
believe that future testing on a larger number of children might display more accurate
results of successes and failures within each age range. While we anticipate that results
might overall yield similar outcomes of this study, if blocking for distance is considered,
we presume that a smaller percentage of participants in the 3-4 year old age group will
34
succeed at the task. We base this on the results indicating that the majority of children
who did succeed in the young age group, only altered the throw kinematics over one
interval. No child in this group altered their throw kinematics for all three intervals. Thus,
we further consider that young children’s success was the possible result of the random
chance that the children tested in this study were, on the whole, more cognitively
developed than the children tested under randomized trials in the preliminary work and
pilot testing. In such case, one could accurately determine that the 3-4 year age range is
the exact range in which children’s cognitive and physical understanding of pretend
throwing tasks is in an emergent yet developing state.
In analysis of the verbal results in Study 2, we noticed that although adult
physical actions illustrated complete consistency among all participants, their verbal
responses in regards to pretend throw lacked homogeny. We proposed that the specific
questioned asked upon completion of throwing trials might not have accurately accounted
for a child’s understanding or lack of understanding in the pretend situation. We further
concede that the question posed to participants was secondary to the imperative
unanswered question regarding the specific tasks utilized in order to alter throws at
different distances in the pretend condition. We encourage future research to incorporate
a more extensive interview conducted post-throwing trials, in which children must be
asked questions such as what/why, if any, specific tasks were used in pretend throws at
different targets.
As the realization to alter questioning in Study 2 was established late in data
collection, we gathered, but did not statistically analyze, some children’s responses in
regards to the reasons why they altered specific pretend throw methods among distances.
35
As an interesting addition to these discussion, we note one particular example in which a
6 year old child verbally explained that alteration of pretend throwing technique was
necessary to reach the 10 meter target because more arm motion and strength is needed to
throw a ball to such a distance. These informal and limited responses urge future
research in order to understand if children’s adult-like pretend throwing patterns observed
within ages 3-7, parallel their ability to verbally explain to the experimenter why they
changed the kinematics of their throwing motions. Some important questions to consider
involve children’s actual choice to alter arm motion based on sight of target distance, or
the possibility that change in arm technique is an intrinsic reflex made based on the visual
input of a greater distance between previous targets. Further, when are children
cognitively aware of the actions they make in pretend throw? The potential results might
speak to a broad variety of psychological issues and children’s developing knowledge of
pretend play.
There were numerous limitations to be expressed in regards to this study. The
initial focus of the study sought to determine the age at which children begin to
understand adult-like actions necessary in a pretend throw task. In light of this, we must
acknowledge that alternations to a study that had been accurately completed by adults,
weakens the significance of children’s success in the altered task. Children’s success in
an altered version of a similar task might only speak to the age range at which children
are able to illustrate adult-like kinematics in their throws when a certain factor is involved
or altered. The internal validity of the study might be called into question if the results are
translated as the single explanation to the original inquiry. We suggest that complete
explanation of the discrepancies observed in Rieser et al’s (2005) preliminary study
36
revolves around a series of factors yet to be determined. Another limitation of the study is
the subjective analysis of video taped test trials necessary to code children’s throwing
patterns. Although the coder used a standardized coding scheme to observe changes in
children’s throwing technique, these calculations require the coder’s subjective opinion,
which might be considered a limitation to the complete accuracy of the study. Further, as
the experimenters coded all video trials, one might suggest that an observational bias
could have influenced the results in relation to the original hypothesis. The validity of
this study would be better accessed if observers unaffiliated with testing trials coded the
videotapes. A final limitation was that each study required a lengthy and extended
patience for the child participant. The study involved a large number of throws that might
have been too rigorous for the child affecting final gathered data.
Besides the suggestions for future research established above, the overall results
of this study coupled with the noted limitations speak to addition directions and future
research that might be conducted as follow up studies to this particular work. As
mentioned above, this paper was to serve the purpose of a controlled follow-up and
addition to the preliminary work of Rieser et al. (2005). It was determined that a
transition in physical understanding of the task presented seems to occur within the age
range of 3-4 year olds and is fully understood by participants in the 5-7 year old age
range. As our participant pools did not consider a greater number of participants per
single age within this block, future studies might explore the differences in cognitive
understand of children of each individual age considered on a larger scale. An enlarged
participants pool for each age might determine the exact age at which participants
transition from complete lack of understanding of pretend throw in the imaginary
37
situation to an obvious and absolute understanding. Thus, if this information is
determined, one might better understand the exact age at which cognitive development in
such areas as pretend play, motor ability as well as visual understanding begins to
approach adult-like capabilities. Additionally, in light of unexpected results in the 3-4
year old age block, future examination of children younger than 3 years of age might
display evidence of pretend throw ability in even younger children than we considered in
this study. This knowledge might then be correlated to children’s verbal understanding of
the physical process to comprehend a greater piece of a child’s ability to determine and
execute action by thought, or thought by action. One should also consider extended
research under randomized distance trials to determine the exact age by which children
(older than 5) begin to understand the pretend throw task without the factor of blocking
for distance.
As experimenter communication was extremely limited to the type of instructions
given to participants, one might suggest that increased explanation of the expectation of
the task might allow a greater number of younger children to succeed in the pretend
condition. The addition of such commands as asking a child to pretend to drop the ball in
the bucket at a close distance or pretend to throw the ball all the way down at the furthest
target might increase a younger child’s understanding of the different technique needed to
reach altered distances. If younger children were to improve with the aid of additional
specific verbal explanation, it may be that the few failures observed in this study were
related to a child’s lack of understanding of the task required of them rather than
cognitive naiveté. The fact that adults succeed in both conditions without elaborate
instruction from the experimenter might be credited to their increased exposure to pretend
38
throw in general. That adults have potentially had more experiences pretending to throw
at different distances requires less experimenter explanation as to what they are being
asked to do in the study.
Although the results in light of the added factor of blocking for distance prove
extremely interesting and unexpected, it is ultimately to be determined the exact reasons
for which children between the ages of 3-7 illustrate the transition observed in the results
of this study and to incorporate these findings into the overall knowledge associated with
children’s development of pretend throwing within early childhood.
39
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Poggio, Tomaso, Bizzi, Emilio. (2004). Gernalization in vision and motor control.
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41
List of Appendices:
1.
2.
3.
4.
5.
6.
7.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Table 1
Distance/Accuracy Scale Sheet
8. Pretend Throwing Kinematics Scoring Guide
42
Figure 1
43
Figure 2
44
Figure 3
45
Median Distance Thrown
12.00
1meter
3meters
5meters
10meters
10.00
8.00
6.00
4.00
2.00
0.00
1
2
3
4
5
6
7
Subject
Figure 4: Median Distance Thrown by 5-7yrolds across different target distances
Figure 4
8
46
Median distance thrown
7.00
1meter
3meters
5meters
10meters
6.00
5.00
4.00
3.00
2.00
1.00
0.00
1
2
3
4
5
6
7
Subject
Figure 5: Median distance thrown by 3-4yr
olds across different target distances
Figure 5
8
47
48
Subject #______
Initials_______
Age_________
School_________________________
Test Trial
Experimenters__________________
First Block
Pretend
Real
T#
Date_____________
Real
Second Block
Pretend
T#
DISTANCE
Target
DISTANCE
Actual
Target
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
12
12
Real Ball
Pretend Ball
Hardest:
Hardest:
Easiest:
Easiest:
Actual
49
Pretend Throwing Kinematics Scoring Guide
(1)Feet
1A = step with correct/opposite foot
1B = step with incorrect/same foot
1C = wt shift (from back foot to front):
1D = stance –feet/body facing forward
1E = stance—body turned/feet at 45 ˚angle
(2)Knees
2A = bend (small)
2B = bend (large)
(3)Trunk
3A = back extension (small)
3B = back extension (large)
3C = rotation
(4)Arm
4A = shoulder (arm brought back behind ear)
4B = elbow (extension)
4C = wrist (snap)
(5)Throwing motion
5A = underhand
5B = overhand
5C = shot put (does not bring arm back behind body;
pushes from in front of shoulder):
(6) Eye
6A
6B
6C
Focus
= steady to target
= looked away nonspecific
= looked at experimenter
(7) Vocal
7A = vocal strain