LOS NIÑOS EN LA GUERRA

I N T R O D U C T I O N

The N3C constraint (Golinkoff et al., 1994), dem onstrated by fast- m apping ability, can be divided into the whole object and m utual exclusivity assum ptions of M arkm an's m odel (Markman, 1992). This experim ent, based on the first p a rt of stu d y 2 in M arkm an and W achtel (1988), exam ines w hether the constraint of the whole object assum ption is used by WS subjects, in an experim ental situation w here the choice is forced betw een a w hole object and its salient p art as the referent for a given word.

Subjects are p resen ted w ith draw ings of objects, together w ith a stim ulus sentence of the form "This is a XXXX", w here XXXX is the nam e of either the whole object or a salient p art of that object. Objects in the draw ings are either fam iliar or unfam iliar to subjects. Subjects m ust indicate w hat XXXX refers to, either the whole object or the part. M arkm an and Wachtel (1988) tested norm al children up to 3 years old and dem onstrated th at as predicted, subjects w ould choose the unfam iliar object above the unfam iliar part in reference to the given word.

No previous research has exam ined w hether children older th an 3 years will dem onstrate a whole object preference to the same degree in this type of procedure. Four groups of control subjects, of m ean ages roughly 3, 5, 7 and 9 years, w ere used to cover approxim ately the range of verbal and performance m ental ages of the WS population tested.

The experim ental procedure is m ore artificial than that used in the previous study of fast-m apping. How ever, given that all WS subjects tested showed fast-m apping ability, it is predicted that they should also show the whole object assum ption, and in the following study, the m utual exclusivity assum ption. These tw o constraints acting in tan d em w o u ld , in these experim ental situations, replicate the action of the N3C constraint th at possession of fast-m apping demonstrates.

M E T H O D

PRELIMINARY STUDIES

Prelim inary study to assess fam iliarity of objects

A large pool of objects was chosen. These were pre-tested on 6 children around the age of 9. They were asked in a production task to nam e the objects depicted in draw ings. Of the familiar objects, those w ere selected of which all the children could give a nam e and gave the same nam e (bar one exception w here 'm ouse' and 'rat' w ere given for the sam e item. Of the unfam iliar objects, those were selected of which none of the children could give a name. It was felt that if the (un)familiarity of the objects was certain for 9 year olds, then this w ould hold for the younger age groups.

Prelim inary study to assess salience of parts

The items chosen by the previous study were assessed for the visual salience of the parts. Ten adults were presented w ith the draw ings, and asked to rate the visual salience of the parts of the objects from 1 to 10 (10 being very prom inent). These were indicated to the subjects. Those objects w ere chosen for final sets, in each condition of fam iliarity, th at h ad no significant difference in the judgem ents of visual salience of parts (p<0.05).

The pool of items used in the experiments is as follows:

TABLE B.IX

EXPERIMENTAL ITEMS USED

CONDITIO N

FAMILIAR

OBJECT PART

mouse / rat tail

house chimney leg foot car wheel camel hum p bottle top television screen bird beak

C O N D ITIO N UNFAMILIAR (normal subjects) (WS subjects) DESIGN OBJECT cafetiere hygrom eter embryo portico pagoda lung amoeba PART plunger ballast radicle ionic (column) finial bronchiole pseudopod

Subjects of control groups and experim ental groups w ere given a stim ulus sentence "This is a XXXX", in conjunction w ith a draw ing of an object w ith a salient part. XXXX referred to either the object or the p art (3 for each, for each subject). The objects were either familiar or unfam iliar to the children (3 of each, for each subject). The subject w as asked to indicate w hether the object was the XXXX or the p art was the XXXX. The design was w ithin-groups for comparison of the effect of familiarity, betw een-groups for comparison of the effect of age.

SUBJECTS

For control subjects, 10 subjects of norm al schoolchildren in each of four age groups were used. These age groups were 3 year old (range of ages 3;0 to 3;10; m ean 3;4), 5 year old (range of ages 5;1 to 5;9; m ean 5;3), 7 year old (range of ages 7;0 to 7;11; m ean 7;6), and 9 year old (range of ages 9;1 to 9;9; m ean 9;4). There w ere an equal num ber of males and females in each of the groups.

For experim ental subjects, 19 WS subjects were tested. Results of 5 of those tested had to be discarded, as they used an alternative response strategy such as alw ays choosing the response indicated first. Of the rem aining 14 subjects, 6 w ere male and 8 female. The m ean age was 20;1, ranging from 7;5 to 31;5 years;months.

MATERIALS

A set of draw ings kept in a lam inated book: Each draw ing w as labelled w ith a letter for easy identification by the experim enter. Two draw ings of

fam iliar objects w ere used for practice items, and six draw ings of familiar objects and six of unfam iliar w ere used for the experim ental items for each subject. These w ere taken from a larger pool of draw ings, from w hich items w ere used for all subjects. The num ber of times any particular draw ing was used w as standardised for betw een age group of control subject. Examples of draw ings are given on page 115.

FAMILIAR OBJECT / FAMILIAR PART

M O U SE / TAIL

UNFAMILIAR OBJECT / UNFAMILIAR PART

PORTICO / IONIC

PROCEDURE

Each subject w as seen individually, sitting opposite the experim enter at a table in a quiet room. The subject was told: "Today we re going to play a game, to do w ith the whole of an object or w ith just a part of it". The subject was given real-object examples of objects w ith parts such as the table and leg, the (experimenter's) face and nose, the (subject's) hand and finger, and w as encouraged to point out any other examples. The subject was then told: "I'm going to show you some things now , and I w an t you to tell me if it's the whole of an object (experim enter drew a large circle w ith his finger on the table) or just a p art of it (experimenter drew a small circle w ith his finger on the table)."

Then the book of draw ings was produced, and the child given two practice items. For each item, before it w as show n, the experim enter w ould say "This is a XXXX", w here XXXX was either the whole object in the draw ing or just the p a rt of it. The draw ing w as then show n to the child and the experimenter said "Which is the XXXX? Is this the XXXX, (experimenter drew a large circle w ith his finger around the whole object), the whole thing? O r is this the XXXX (experim enter drew a small circle w ith his finger around the part), this part?". The second practice item w as either the part or whole object, depending on w hich was used first. The subject w as encouraged to m ake a response using their finger to mimic the experim enter. If the subject m ade a

m istake d uring the practice items, the experim enter w ould explain w hy that response was w rong until the child m ade the correct response and appeared to understand why.

Then followed six familiar object experim ental trials alternating w ith six unfam iliar object experim ental trials. The procedure w as exactly that of the practice items, except that no extra help was given if the subject m ade a m istake and the subject's first firm response w as taken as the response. W hether the object or the p art w as indicated first by the experim enter w as counter-balanced across trials.

A t the end of the task, the subject was asked for each practice and experim ental item in turn "Can you tell me w hat this thing is called? If you do n 't know , then either m ake a guess if you think you m ight be right, or otherw ise just say you don't know", in the order of presentation during the experim ent proper. The nam e given by the subject was recorded. The num ber of object responses m ade by each subject in each of the categories of familiar and unfam iliar objects was summed.

The experimental hypotheses are:

CONTROL SUBJECTS HYPOTHESES

for effect o f fam iliarity

H I: hypothesisi states that for the familiar objects and parts, the child will be able to select either object or p art as referred to. For unfam iliar objects and parts how ever, the child will use the whole object assum ption and select the object response exclusively.

H I: hypothesiso states that for the familiar objects and parts, the child will be able to select either object or p art as referred to. For unfam iliar objects and parts how ever, the child w ill select random ly or by some other heuristic either object or p art w ith equal frequency.

Idealised results then:, to support H li:

fam iliar : object I part unfamiliar : object / part

hypothesis! 3 /3 6 /0

hypothesiso 3 /3 3 /3

fo r effect of age

H2: h y p o th esis! states th at there w ill be no significant effect on the familiarity effect (object bias) by the age of the subjects.

H2: hypothesise states that there will be a significant effect on the familiarity effect (object bias) by the age of the subjects.