The purpose of this experiment is to learn
about crossed hand eye dominance and help
increase free throw percentage in basketball.
This project is designed to look for consequences
of having the dominant hand and eye on the same
side of the body (uncrossed) vs. having the
dominant hand and eye on opposite sides of the
body (crossed).
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Data from previously done experiments support our
hypothesis. One experiment done by Keith Hines and
Robert Thurman stated that crossed hand-eye
dominant people have a higher free throw percentage
than uncrossed hand-eye dominant people. Another
experiment proved the same results. This project was
conducted by Ashton W. Pomrehn, who found that
crossed hand-eye dominance has a positive effect on
basketball players. It makes logical sense that crossed
hand-eye dominance would have a positive effect on
free throw percentage because if you have uncrossed
hand-eye dominance, your dominant eye is blocked
by the hand shooting the basketball.
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Some key terms are: dominance- the normal tendency for one side of the
brain to be more important than the other in controlling certain
functions, as speech and language: crossed- mixed, usually with two
components; and, eye dominance- the tendency to prefer visual input
from one eye to the other. More key terms are: hand dominance- the
preference of one hand to perform fine and gross motor tasks; and,
crossed hand eye dominance- having opposite dominances in eyes and
hands. There are a few key points to know while conducting this
experiment. "Eye Dominance" refers to the eye that the brain "prefers"
or one that has stronger "processing" in the brain than the other. People
usually have one eye that likes to "take over" when binocular vision is
impaired, or one eye that is more sensitive to visual
discrimination. During suppression, when the brain "chooses" to process
only one eye, the other eye is in essence "shut down". Usually it makes no
difference in correcting for visual defects with eyeglasses or contacts.

If one is crossed hand-eye dominant, then their shooting percentage will
increase because when players shoot free throws, they often hold the
ball up at face-level when preparing for the shot. In this position, the ball
can easily the eye on the same side of the body as the shooting hand. For
shooters with uncrossed hand and eye dominances, this would mean
that the dominant eye was partially blocked. For shooters with crossed
hand and eye dominances, this would mean that the non-dominant eye
was partially blocked. The independent variable is if you are cross handeye dominant, and the dependent variable is how many free-throws you
make. Eye dominance refers to the eye that the brain prefers, or one that
has stronger processing in the brain than the other. People usually have
one eye that likes to take over when binocular vision is impaired, or one
eye that is more sensitive to visual discrimination. During suppression,
when the brain chooses to process only one eye, the other eye is in
essence shut down. Usually it makes no difference in correcting for visual
defects with eyeglasses or contacts.

If 20 people shoot free throws in this
experiment, then people with crossed handeye dominance will make more free throws
then those without crossed hand-eye
dominance.

The independent variable to this experiment
is if you are crossed hand-eye dominate.

The dependent variable is how many free
throws you make.

The control to this project is being crossed
hand/eye dominate.
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Pen/pencil
Paper
10 people
Clipboard
Basketball court
Basketball

First, gather 20 people

Then gather information about the participants such as name, age, etc.
Have each person test to see whether they are crossed hand-eye dominant or not
the person would extend both hands away from the body and place the hands together making a
small triangle (approximately 1/2 to 3/4 inch per side) between the thumbs and the first knuckle.
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With both eyes open the person would then look through the triangle and center something such
as a doorknob in the triangle.

Close the left eye

.If the object remains in view, the subject would be right eye dominant. If the subject’s hands
appear to move off the object and move to the left, then the subject would be left eye dominant.
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After, record if the person is right or left handed. If the person has different hand and eye
dominance, then mark them down as crossed hand-eye dominant.
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Next have the person shoot 5 free throw shots at a basketball hoop with their dominant hand.
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Finally record whether or not the shot was made.
Subject
Age
Subject 1
12
Dominant
Hand
Right
Dominant
Eye
Right
Crossed or Uncrossed?
Subject 2
13
Right
Left
Crossed
9
Subject 3
12
Right
Right
Uncrossed
9
Subject 4
12
Right
Right
Uncrossed
8
Subject 5
12
Right
Right
Uncrossed
9
Subject 6
12
Right
Right
Uncrossed
9
Subject 7
12
Right
Right
Uncrossed
7
Subject 8
12
Left
Right
Crossed
10
Subject 9
12
Right
Left
Crossed
6
Subject 10
12
Right
Right
Crossed
7
Uncrossed
Shots Made
8
While people were shooing I noticed that
everyone that was crossed eye was having
the same movement. That’s really when I
understood the science of simply shooting a
basketball.
Percentage Made
120%
100%
80%
60%
40%
20%
Uncrossed
Uncrossed
Uncrossed
Crossed
L
Uncrossed
Uncrossed
R R R R R R R
Uncrossed
R
Uncrossed
Crossed
L
Uncrossed
Crossed
R R R R R R R R R
Uncrossed
Crossed
L
Uncrossed
R R R R R R
Uncrossed
Uncrossed
L
Uncrossed
Crossed
R
Uncrossed
Uncrossed
0%
R R R R R R R R R R R R
12 13 12 12 12 12 12 12 12 12 12 13 12 13 12 13 12 13 12 12
Percentage Made
The results were very scattered, and the
hypothesis of my experiment was proved wrong.
It is now understood that hand eye dominance
does not effect free-throw shooting as much as
the hypothesis stated. Some further
investigations could include testing if crossed
hand-eye dominance effected hand-eye
coordination, if air pressure will affect the
dynamics of ball bouncing, or if bodies are leftdominant or right-dominant effects any certain
thing.

After gathering our data, it was concluded that crossed
hand-eye dominance doesn’t have much of an effect on
free throw shooting percentage. The hypothesis stated
that crossed hand-eye dominance will help basketball
players score free throws because, when players shoot
free throws, they usually hold the ball up at face level,
which can easily block the eye on the side of the shooting
hand. On the other hand, shooters with crossed hand-eye
dominance would have their non-dominant eye partially
blocked, which wouldn’t affect them much. The results, on
the other hand, didn’t agree with our hypothesis. When
subjects shot a free throw both crossed and uncrossed
averages resulted in a 8-shot-made average. From the
averages we collected, the hypothesis was inaccurate.

Hines, K., & Thurman, R. (2007, April 2). Ballin': The
Effect of Hand and Eye Dominance on a Subject's Free.

Kirillov, A., & Beverly, C. (2011, October 9).
Determining your Dominant Eye.

McWilliams, K., & Armstrong, P. (1998, November 28).
What is Eye Dominance?

Olson, A., Ph.D. (2007, October 1). Crossed Up: Does
Crossed Hand/Eye Dominance Affect Basketball
Shooting Percentage? Retrieved October 15, 2011