Perceptual and Mocor Skills, 1976,43, 175-178. @ Perceptual and Motor Skills 1976 TEST O F T H E INCIDENTAL-CUES HYPOTHESIS1 MlCHEL DENIS? Universitk de Paris S,Nanterre Summary.-Five groups of adult Ss were submitted to free-recall learning of 24 objects presented as written nouns for the control group and as pictures for experimental groups, as follows: schemacic black and white, schematic colored, detailed black and white, and detailed colored drawings. Pictures were better recalled than nouns. Recall was significantly inferior for schematic black and white than for derailed colored drawings, with schematic colored and detailed black and white drawings at an intermediate level. These results support the so-called incidental-cues hypothesis according to which the best recall of pictures in comparison with that of nouns is partially the result of pictures having more distinctive cues likely to be encoded than do verbal items. Among the hypotheses which account for the superiority of the recall of pictures over rhat of nouns, the so-called incidental-cues hypothesis has been asserted. According to this hypothesis, the first formulation of which appears to have been presented by Jenkins, et al. ( 2 ) , the best recall of pictures, as compared co chac o f nouns, would be explained by the fact chac pictures concain more distinctive cues which make them more discriminable than nouns. For instance, the word "child" contains many fewer cues likely co be encoded chan the pictorial representation of any particular child, with any given characteristics, wearing certain clothes, in a certain setting. T h e richness of the picture in cues of this type, even if chey are noc specific to the concept in question, increases che discriminabilicy of the item relatively co the ocher items of che list, buc also relatively to individual's experiences prior to this learning. T h e greater discriminability of pictorial items contrasts with the formal, typographical similarity which characterizes che verbal items. This would explain, at least partially, the better memory scores for concrete or pictorial materials. The hypothesis according to which the addition of such distinctive cues has a positive effect on memorizing a list of piccures can be tested within the field of concrete objects. Thus, at the most elementary level, one may have to deal wich schematic representations of objects; those representations can also be enriched by various details, even colors; the realism of the representations can also be increased by the substitution of photographs for those drawings; finally, one can resort to the objects themselves. In a first case, it appears that those different materials may produce identical recall relative to a control condicion This research work has been undertaken in the Equipe de Recherche associke au CN.R.S. no. 191. Jean Chaguiboff and Christine Colonelli efficiencly contributed to the collection and analysis of the data. 'Author's address: Universite de Paris X, Laboratoire de Psychologie de la Culture (E.R.A. au C.N.R.S. no. 191), Centre universitaire Saint-Charles, 162, rue Saint-Charles, 75740 Paris Cedex 15. France.
(nouns only). One could conclude that the effects of pictorial representation come into play through an all-or-nothing phenomenon. The other case, i.e., increase in performance as one moves from one situation to another, would considerably reinforce the hypothesis according to which the efficiency of pictorial representation passes through encoding of supplementary cues, certainly more or less superfluous for the definition of the concepts to be learned but enhancing the discriminabiliry between the items. In chis respect, literature only furnishes partial data. The role of realism of the picture and of color has been examined, often with contradictory results, and the two variables have not always been dissociated. Thus, Wicker ( 5 ) , varying simultaneously color and the realism of representation, compared the use of schematic drawings in black and white and of color photographs of the same objects as stimulus terms in a paired-associate learning task with concrete nouns as response terms. The total number of trials to reach the criterion of learning was not statistically different for one or the other type of material. More recently, Nelson, et al. ( 3 ) recorded similar recognition scores for scenes presented in the form of photographs, of drawings with details and of drawings without details. The positive effect of color in memorizing pictures was demonstrated by Bousfield, et al. ( 1 ), who have shown that a list of nouns accompanied by colored drawings was better recalled than the same list of nouns accompanied by the same drawings in black and white. However, in a similar free-recall learning task, this effect of color was not obtained by Paivio, et al. ( 4 ) . In the present experiment, these rwo variables have been handled within a factorial design which allowed an examination of their possible interaction: realism (each one of the retained objects existed under a schematic representation or endowed with numerous details) and color (each drawing, schematic or detailed, existed in two forms, black and white or colored). The combination of those two variables led to the constitution of four versions of the material: schematic black and white, schematic colored, detailed black and white, and derailed colored. Testing of the incidental-cues hypothesis was made by comparing recall scores for four independent groups of Ss who learned the four lists. A control group learned nouns only. METHOD The list learned by control Ss had 24 concrete nouns which were French equivalents of the following ones: airplane, axe, banana, barrel, bell, bird, book, bottle, bread, butterfly, carrot, chair, cigar, clock, cup, cupboard, drum, fish, flag, house, shoe, tree, trumpet, umbrella. Four lists of pictures corresponded to the list of nouns. List 1 consisted of drawings made with relatively schematic black lines against white background, presenting the objects under a familiar angle. List 2 had the same drawings as the previous ones, enriched by numerous details and specifying elements. Lists 3 and 4 were composed respectively with List 1 and List 2 drawings, to which the color (or colors) charaaeristic of the objects had been added. A pilot study showed all those drawings could be easily recognized and unequivocally labeled. For each of the five conditions, the list of 24
177
INCIDENTAL-CUES HYPOTHESIS
items was presented three times. Before each presentation, Ss received standard free-recall learning instructions. At the end of each presentation, 2 min. were allowed for written recall of remembered items. Three orders of presentation-A, B, and C-were drawn at random. One took steps to assure that items which could present a certain semantic or phonetic proximity would not be in immediate succession. Within each of the five conditions of the experiment, the material was presented in three modalities with order of presentation controlled, i.e., successively in the orders A, B, and C, for a third of the Ss; in the orders B, C, and A, for another third; and in the orders C, A, and B, for the last third. Material was presented on slides. The time of presentation was 2.5 sec. per item. with 1.5-sec. interitem intervals. Ss were 120 students from the University of Paris X, aged 17 to 34 yr. Each was randomly assigned to one condition. For each condition, there were 8 Ss for each of the three modalities constrained by order of presentation, i.e., a total of 24 Ss (wich 7 to 9 males). Ss were examined individually or in small groups of 2 or 3 individuals.
RESULTSAND DISCUSSION Table 1 presents mean recall scores on the three trials for the five conditions. Data were analyzed according to the procedure described by Winer (6, pp. 468-473) for factorial experiments with a control group. The factorial part of the design was 2 X 2 X 3, with realism and color as between-subjects factors, and trials as a within-subjects factor. The analysis allows one to consider that the four conditions using drawings produced better recall scores than the control condition using nouns only ( F = 18.69, df = 1/115, p < .001). Application of Dunnett's test shows that those four conditions gave higher performances than the control condition ( p < .05).
.
TABLE 1 MEANCORRECTRECALLSCORES (-CSD) Condition
Trial 1
Trial 2
Trial 3
Nouns Schematic black and white drawings Schematic colored drawings Detailed black and white drawings Detailed colored drawings
11.04&2.46 12.29e2.53 13.8322.75 12.75k2.21 1 4 . 0 8 f 2.55
15.00k3.22 16.96e2.53 17.58k3.30 17.9622.44 18.7522.38
17.4223.16 18.88e2.86 18.5822.99 19.67k2.08 20.0821.89
Trials are a significant factor ( F = 496.89, df = 2/230, p < .001). If one examines the effects of between-subjects factors, one finds that, on the whole, detailed drawings are somewhat better recalled than schematic ones and that colored drawings are better recalled than those in black and white. However, the over-all effects of realism and of color do not reach significance, probably due to the fact that differences between the four conditions rapidly decreased from Trials 1 to 3. In fact, color had obviously positive effects on Trial 1, the Color X Trials interaction being significant ( F = 4.69, df = 2/230, p .01). N o other significant interaction could be observed, including the interaction of Realism X Color.
(nouns only). One could conclude that the effects of pictorial representation come into play through an all-or-nothing phenomenon. The other case, i.e., increase in performance as one moves from one situation to another, would considerably reinforce the hypothesis according to which the efficiency of pictorial representation passes through encoding of supplementary cues, certainly more or less superfluous for the definition of the concepts to be learned but enhancing the discriminabiliry between the items. In chis respect, literature only furnishes partial data. The role of realism of the picture and of color has been examined, often with contradictory results, and the two variables have not always been dissociated. Thus, Wicker ( 5 ) , varying simultaneously color and the realism of representation, compared the use of schematic drawings in black and white and of color photographs of the same objects as stimulus terms in a paired-associate learning task with concrete nouns as response terms. The total number of trials to reach the criterion of learning was not statistically different for one or the other type of material. More recently, Nelson, et al. ( 3 ) recorded similar recognition scores for scenes presented in the form of photographs, of drawings with details and of drawings without details. The positive effect of color in memorizing pictures was demonstrated by Bousfield, et al. ( 1 ), who have shown that a list of nouns accompanied by colored drawings was better recalled than the same list of nouns accompanied by the same drawings in black and white. However, in a similar free-recall learning task, this effect of color was not obtained by Paivio, et al. ( 4 ) . In the present experiment, these rwo variables have been handled within a factorial design which allowed an examination of their possible interaction: realism (each one of the retained objects existed under a schematic representation or endowed with numerous details) and color (each drawing, schematic or detailed, existed in two forms, black and white or colored). The combination of those two variables led to the constitution of four versions of the material: schematic black and white, schematic colored, detailed black and white, and derailed colored. Testing of the incidental-cues hypothesis was made by comparing recall scores for four independent groups of Ss who learned the four lists. A control group learned nouns only. METHOD The list learned by control Ss had 24 concrete nouns which were French equivalents of the following ones: airplane, axe, banana, barrel, bell, bird, book, bottle, bread, butterfly, carrot, chair, cigar, clock, cup, cupboard, drum, fish, flag, house, shoe, tree, trumpet, umbrella. Four lists of pictures corresponded to the list of nouns. List 1 consisted of drawings made with relatively schematic black lines against white background, presenting the objects under a familiar angle. List 2 had the same drawings as the previous ones, enriched by numerous details and specifying elements. Lists 3 and 4 were composed respectively with List 1 and List 2 drawings, to which the color (or colors) charaaeristic of the objects had been added. A pilot study showed all those drawings could be easily recognized and unequivocally labeled. For each of the five conditions, the list of 24
177
INCIDENTAL-CUES HYPOTHESIS
items was presented three times. Before each presentation, Ss received standard free-recall learning instructions. At the end of each presentation, 2 min. were allowed for written recall of remembered items. Three orders of presentation-A, B, and C-were drawn at random. One took steps to assure that items which could present a certain semantic or phonetic proximity would not be in immediate succession. Within each of the five conditions of the experiment, the material was presented in three modalities with order of presentation controlled, i.e., successively in the orders A, B, and C, for a third of the Ss; in the orders B, C, and A, for another third; and in the orders C, A, and B, for the last third. Material was presented on slides. The time of presentation was 2.5 sec. per item. with 1.5-sec. interitem intervals. Ss were 120 students from the University of Paris X, aged 17 to 34 yr. Each was randomly assigned to one condition. For each condition, there were 8 Ss for each of the three modalities constrained by order of presentation, i.e., a total of 24 Ss (wich 7 to 9 males). Ss were examined individually or in small groups of 2 or 3 individuals.
RESULTSAND DISCUSSION Table 1 presents mean recall scores on the three trials for the five conditions. Data were analyzed according to the procedure described by Winer (6, pp. 468-473) for factorial experiments with a control group. The factorial part of the design was 2 X 2 X 3, with realism and color as between-subjects factors, and trials as a within-subjects factor. The analysis allows one to consider that the four conditions using drawings produced better recall scores than the control condition using nouns only ( F = 18.69, df = 1/115, p < .001). Application of Dunnett's test shows that those four conditions gave higher performances than the control condition ( p < .05).
.
TABLE 1 MEANCORRECTRECALLSCORES (-CSD) Condition
Trial 1
Trial 2
Trial 3
Nouns Schematic black and white drawings Schematic colored drawings Detailed black and white drawings Detailed colored drawings
11.04&2.46 12.29e2.53 13.8322.75 12.75k2.21 1 4 . 0 8 f 2.55
15.00k3.22 16.96e2.53 17.58k3.30 17.9622.44 18.7522.38
17.4223.16 18.88e2.86 18.5822.99 19.67k2.08 20.0821.89
Trials are a significant factor ( F = 496.89, df = 2/230, p < .001). If one examines the effects of between-subjects factors, one finds that, on the whole, detailed drawings are somewhat better recalled than schematic ones and that colored drawings are better recalled than those in black and white. However, the over-all effects of realism and of color do not reach significance, probably due to the fact that differences between the four conditions rapidly decreased from Trials 1 to 3. In fact, color had obviously positive effects on Trial 1, the Color X Trials interaction being significant ( F = 4.69, df = 2/230, p .01). N o other significant interaction could be observed, including the interaction of Realism X Color.
