Methoden der Sprachwerbsforschung
(mit einigen Folien aus „EXPERIMENTAL PARADIGMS
IN DEVELOPMENTAL PSYCHOLINGUISTICS“ von
Zsuzsanna Schnell (Institute of Psychology, University of
Pécs
Typology of methods
Distinction based on:
• 1. Sample: Longitudinal vs. Cross sectional
• 2. Method: Observation based (diaries, questionnaires) vs.
Experimental
• 3. Temporal aspect: Pre-natal vs. Post natal
• 4. Linguistic behavior: Pre-verbal vs. Verbal
Research methods in the study of language
development
• Diaries and parental reports:
as early as 18th century – own children, diaries.
• remain a valuable source,
!: misleading: tempted to write down unusual,
or interesting, and not the ordinary but relevant.
• new version: McArthur Communicative Development
Inventory (CDI) by Larry Fenson et al.
• checklist prepared by psycholinguists distributed to parents
• has been validated in laboratory settings.
Advantages vs. Disadvantages
•
•
•
•
ADVANTAGES: natural setting, family context
fast, no funding needed
no training required
DISADVANTAGES: not suitable for older children,
whose lg use is more complex
• may be misleading
• ALL IN ALL: If used correctly, the home-based
parental questionnaire is a reliable indicator
Observational data
• first motivation: reconcile allegations
of revolutionary nativism: UG, LAD
• first: tape recordings  transcripts.
• Roger Brown 1960-ies, Harvard:
longitudinal study, studying the lg dev.
of Adam, Eve and Sarah.
 transcripts fostered our understading of child grammar, acq.
of basic sentence structures
• still a major research design
Advantages vs. disadvantages
ADVANTAGES:
• rich source of data.
• focus on environmental factors and on influence of
socialization (effect of parental input).
DISADVANTAGES: longitudinal studies are
- confined to a small n. of children (luckily results are representative of
all children)
!:transcripts may not include all situational factors, social and contextual
effects
- Difficulties arise from individual encoding – devising their own system,
rendering it unusable for others.
CHILDES – The Child Language Data Exchange System
http://childes.psy.cmu.edu
•
•
•
•
unified approach
standardization in research methods,
of recording and analyzing data on child language production.
1980’s: Brian MacWhinney and Catherine Snow proposed setting up a
computerised data-base that would be available for the entire academic
community.
CHILDES
http://childes.psy.cmu.edu
• the database can be accessed worldwide, to which relevant
material can be contributed in a standard format.
• today contains data from 22 lgs
• on both first LA and second lg learning
• from normally and from atipically developing children
• from early mother-child dialogues to lengthy narratives,
monologues
• prosody, stress, pause patterns, metalinguistic fators.
• Allows initial assessment of hypotheses.
@UTF8
@Begin
@Languages: nl
@Participants: 024 Patient, DIE Dieke_Lagers Investigator
@ID:
nl | frogstory | 024 | | | fs | | Patient | |
@ID:
nl | frogstory | DIE | | female | fs | | Investigator | |
@Coder: Neeltje Verstegen
*DIE:
ja, wat gebeurt (e)r verder?
*DIE:
zullen we (een)s verder kijken?
*024:
een hond die ging # de jongen likken.
%pro:
$1
*024:
en die jongen kijk(t) [*] <zo naar> [?] buiten.
%pro:
$1
%err:
$5 kijk = kijkt
*024:
0er viel een hond # viel van xxx.
%pro:
$1
%err:
$8
*024:
en in een keer valt die glazen pot.
%pro:
$1
*024:
[=! laughs].
Longitudinal vs. Cross-sectional studies
• Cross sectional studies: gather groups of children to assess
their abilities
• compare performance of groups.
• ADVANTAGES: allows to obtain a great deal of data in a
short time,
• large samples yield results that can be generalized.
• Cross Sectional or Longitud. studies can be either
Observational or Experimental.
Observational studies
The researcher tries not to interfere with the subject’s
natural use of lg.
a.) Naturalistic O.S. - focus on real-life situations 
linguistic socialization, env. factors shaping LA
b.) Controlled O. S. – laboratory setting and props are
the same for all subjects (puppets).
Experimental studies
Do involve interference from the part of the researcher.
• WUG test - Jean Berko Gleason ’50-ies – Elicited Production
experiment Using Nonce Words.
• m.i.: when prompted by the linguistic context in which the
term appears, children will transform these so as to obey the
grammatical rules.
• picture shown and is told it is called a „wug”. Then subject is
shown another „wug” and told: „So now there are 2 of them.”
And asked: „Now I have two…?” Expected answer: „wugS”.
• 2. Every day I „gorp”. Just like every day, yesterday I……….?
„GORPED”.
Berko (1958)
13
Observational vs. Experimental studies
• OS: we do not know for sure if plural marker „s” is consciously
put there, or blind imitation
• ES: semi-controlled setting, eliciting the plural marker  RULE
application  true status of grammatical markers
DISADVANTAGE of ES:
• Rigidly controlled settings may mean difficulties, such
demands of the experimental task may distort validity and
reliability of results.
• It is therefore important to verify that such patterns are
present in natural speech.
PREVERBAL I.
Pre-natal Studies of speech perception
Prenatal (fetal):
from 6th month of gestation
method: microphone placed outside the womb,
measure modifications in:
a.) Cardiac acceleration/deceleration:
fetus shows sensitivity to changes
in stimuli (habituation)
b.) Fetal movement (kicking rate)
corresponds to changes in stimuli (US)
PREVERBAL II.
Post-Natal Studies of speech perception
HASP: High Amplitude Sucking Paradigm
(e.g. Juszyk, 1997)
?: categorical perception of infants
capitalizes on natural sucking instinct
using sucking rate
as measure of interest
habituation / dehabituation
paradigm
…with older children
• Conditioned head-turn paradigm
(Polka, Jusczyk, Rvachew 1995)
- with infants 6-18 months of age
-a stimulus sound is presented
repeatedly
• - Whenever there is a change in a stimulus, an electric toy (to
the side of the child’s line of vision. ) is lit up and activated.
• Eventually the child learns to anticipate that sound
changes provoke a visual display, and they will turn
their head to look for it when hearing a sound
change.
methods for studying comprehension …beyond speech
(sound) perception
• preferential looking paradigm
(Hirsh-Pasek – Golinkoff 1996).
capitalizes on
differential looking behavior
when given a choice from 2 displays
 child grammar: passive voice
 lexicon: pictures of objects, animals (nouns)
 m.i.: child will look longer in the direction of the named object if they
understand the word / construction.
 if neither object corresponds to the experimenter’s label, then they will
look at both stimuli for eqivalent periods of time.
 the same holds if the baby does not know the word.
…in the verbal stages
• elicited response, interviews (monologue, retelling an adventure>5
yrs).
 Off-line techniques
measure comprehension by getting children
a.) perform an action (act out)
b.) retell the event after hearing a linguistic stimulus
c.) picture pointing – subject is asked to point to the pic. that depicts
the action in the experimenter’s utterance.
The dog pushes the cow
vs.
The cow is pushed by the dog
(active vs. passive)
DISADVANTAGE:
experimenter influences answers (multiple choice)
- involves conscious decisions and reflections by the child (performance
limitations) (metalinguistic competence.)
On-line techniques I.
-
measure language processing as it occurs in real time.
e.g.: distinction between transitive vs. intransitive verbs.
-
I. Task: to listen for a particular word, e.g. „DOG”.
The subject is asked to push a button as soon as they hear the target
word.
a.) The boy was out on a walk and he watched a DOG passing by.
b.) The boy was out on a walk and he watched to*a DOG passing by.
If they are sensitive to in-/transitive distinction, it will take longer to react
in the erroneous case (watched to* a DOG…)
because the processing of ungrammatical structures will take longer if
they have already acquired the correct grammatical rule.
-
On-line techniques II.
- Non-invasive brain imaging studies: HD Event Related
Potential (ERP) Studies measuring electric activity in brain
areas.
- Eye-tracking experiments (head-mounted and remote eyetracking systems) (syntactic parsing, topicality, idiom research
looking time – segmentation correlation).
- Reaction-time techniques: computers measure reaction time
in milliseconds. Time correlates with parsing difficulties
(gaden-path sentences).
Advantages vs. Disadvantages
of on-line methods
-
ADVANTAGES:
fast, accurate,
reveals fine-grained differences in performance,
memory is not overburdened, does not require reflection, since it is
unconscious.
reveal competence off-line don’t (focus on comprehension)
- online: investigates the interaction between competence and
performance factors.
-
DISADVANTAGES:
difficult to design,
fallible, detail sensitive.
Conclusions
• Innovative Experimental techniques counterbalance
the limitations of a purely observational research
• Experimentally gained data need to be
complemented by observations of natural linguistic
performance.
Literature:
E. Blom & S. Unsworth (2010) siehe Lehrmaterialien
Gleason, J. B. - Ratner, N. B. (1998). Psycholinguistics. Harcourt Brace College
Publishers. Orlando, FL.
Karmiloff-Smith, A. – Karmiloff, K. (2002). Pathways to Language. Harvard
University Press.
Sowden, H. (2008). Developmental Psycholinguistics. On-line methods in
children’s language processing. Language acquisition and language
disorders series. John Benjamins, Amsterdam.
Head-turn preference procedure (Kemler Nelson,
Jusczyk, Mandel, Myers, Turk & Gerken, 1995)
(used with children 5-20 months old, but mainly with 6-12-montholds)
For this method we make use of a 3-sided booth. The child sits facing forwards
on the parent’s lap in the middle of the booth. In the centre of the wall facing
the child is a blue light that starts to blink at the beginning of the experiment.
When the child looks at the light, it stops blinking, but a red light on either the
left or right side of the booth then starts to blink. There are loudspeakers built
into the wall behind the lights. As soon as the child looks at the light on the left
or right, he will hear a speech sample. The sound stops if the child looks away
for more than two seconds. So the length of the speech sample is dependent
on how long the child continues to look at the light. When the sound stops, the
blue light in front of him will blink again to attract his attention and the whole
process starts again. By measuring the time spent listening to different speech
samples, we can discover whether the child has a preference for one of them.
We use this method to find out whether children have a preference for (and
thus listen longer to):
their native language as compared to another language;
grammatical as opposed to ungrammatical sentences;
frequently-occurring as opposed to infrequently-occurring words;
words with stress on the first syllable (“baby”) as opposed to words with stress
on the second syllable (“giraffe”).
Baby Research Center Nijmegen
The Conditioned Head-Turn Procedure (CHT, Polka, Jusczyk, & Rvachew
1995)
(between 6 and 10 months of age)
Sitting across a table (on a parent’s lap) from an experimental assistant,
the infant is shown brightly coloured toys to keep him/her interested and
focused straight ahead. Speech stimuli are presented to the infant via an
audio speaker placed at one side. The infant is taught to turn his/her
head in the direction of the sound whenever there is a change in the
speech stimulus. A correct head-turn results in visual reinforcement from
the direction of the audio speaker; the experimental assistant also gives
the infant social reinforcement via smiles and praise. Incorrect headturns are not reinforced.
A study using the CHT begins with a Conditioning phase, during which
tokens from the background stimulus category are played repeatedly so
that the infant gets used to that category of sounds (e.g., ba, ba, ba, ba).
Then, the target sound (or sound category) is played (e.g., da), and after
a short delay of a few seconds, the reinforcer (a lighted, moving toy
bunny that plays on a set of drums) turns on, prompting the infant to
make a head turn. This sequence is repeated a number of times so that
the infant becomes conditioned to turn his/her head toward the bunny
when he/she hears the change in sound from the background stimulus to
the reference stimulus.
Eye-tracking
The equipment we use for measuring eye movements (the Tobii eye-tracker) consists of a
computer screen with a built-in camera that takes pictures of your child’s eyes. Your child
will sit on your lap and watch a short movie on the computer screen.
While your child is watching the movie, we record his or her eye movements and later
investigate whether and how he or she followed what happened on the screen and
which aspects he or she paid most attention to.
Before the measurement can begin, your child will see a circle moving to different
positions on the screen. In this first phase of the experiment it’s important that your child
looks at the circles and doesn’t move around too much. In this way, the computer can
register what your child’s eyes look like when he or she looks at different parts of the
screen. This usually takes just one or two minutes. The main experiment then starts,
during which your child will watch one or two short movies. Generally, each experiment
lasts only a few minutes, but if your child becomes very restless, we can simply end the
experiment.
The eye-tracker allows us to learn how babies perceive and process other people’s
actions. The picture below is from a study where we investigated whether babies already
know what various objects are used for. The pictures show the child watching as a person
picks up a cup (the child’s eye movements are shown by a blue dot.) It’s very clear that
the child has anticipated what the person is going to do!
Baby Research Center Nijmegen
Eye-tracking
Preferential looking paradigm (Hirsh-Pasek – Golinkoff 1996)
(used with children aged 4-26 months old)
One of the methods we use is the “Preferential Looking Paradigm”. We observe children’s
eye movements while they watch a short movie either on a large TV screen or on a Tobii
eye-tracker. The children sit on their parent’s lap. The parent generally listens to music via
headphones so that he or she doesn’t influence the child in any way. The movies, in which
the child either hears words, sentences or a story generally last no longer than 5 minutes. If
a child hears the name of an object that is depicted on the screen, then he or she will
automatically look at that object. For example, if the screen shows a dog on the right and a
baby on the left and the child hears “Where’s the baby?”, then the child will look at the left
side of the screen. In one of our experiments, we investigated whether children would also
do this if they heard “Where is the “vaby”? It appears that in this situation children will look
at the correct picture (the baby), but it will generally take a little longer and they will look at
the picture for less time.
Children also sometimes mispronounce words. For example, a Dutch word like “vis” may
often be pronounced “tis”, and “vogel” may be pronounced “pogo”. But a word like “poes”
won’t normally be pronounced as “voes”. It appears that how a word is pronounced
depends on children’s perception of it: children easily notice the difference between “voes”
and “poes”, but less easily the difference between “vogel” and “pogo”.
Baby Research Center Nijmegen
Switch procedure (Stager & Werker, 1997) (Variant of visual
fixation procedure)
In the Switch procedure we measure the eye movements of young children while they are
looking at a picture or some other visual display on a large TV screen. While they are looking
at the screen, they hear various sounds, words or languages. The child sits on the parent’s
lap, while the parent listens to music via headphones, so that he or she doesn’t inadvertently
influence the child’s behaviour. Children can often hold a plastic toy during the experiment.
The majority of experiments last for five minutes. The idea behind this procedure is for the
child to listen to a word, for example, long enough that he or she no longer finds it
interesting and looks away from the screen more and more frequently. This is also known as
“habituation”. We determine the child’s interest based on how long he or she continues to
look at the screen. When the child’s interest has decreased considerably, we let him or her
listen to another word (that is sometimes very similar to the previous one). If children notice
the difference between the new word and the previous one, then their interest should
increase and they should once again spend more time looking at the screen.
Our research using this procedure has shown that 10-month-olds are able to discern small
sound changes at the beginning of words. For example, infants continuously heard the
fictitious word “tos” and after a while gradually lost interest and spent less time looking at
the screen. When they subsequently heard a new fictitious word “pos”, where the beginning
of the word changed from “t” to “p”, the time they spent looking at the screen increased
again.
Baby Research Center Nijmegen
Aufgabe v. 20.4.15
Lesen Sie das Kapitel von Johnson & Zamuner (S 73ff) in Blom & Unsworth
(2010). Nennen Sie Vor- und Nachteile der Methoden.
Erstellen Sie eine Zeitskala in Monaten von 0-24 aus der ersichtlich wird,
welche Methoden in welchem Alter in Frage kommen (einschließlich
conditioned head-turn procedure und high-amplitude sucking procedure, siehe
Folien)
Bereiten Sie mit zwei bis drei weiteren Teilnehmer(inne)n eine kurze (ca. 5
min.) Demonstration einer der Methoden in Form eines Rollenspiels vor.
Achtung: Außer den beteiligten Personen (Kind, Mutter, Experimentator,
Sprecher von Stimuli) brauchen Sie auch Requisiten (Licht, Spielzeuge).