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Nonverbal information storage in children and developmental information processing channel capacity
Nonverbal
information
Storage
Developmental Information Channel CapacitylJ BIKKAR University
S.
in Children
and
Processing
RANDHAWA
of Snskatchezca~l,
Saskatoon,
Cnncctla
The present study was designed to test Glnnzcr and Clark’s “verbal loop hypothesis” using children at various developmental levels. In particular, this study attempted to test whether the information output from “pure” verbal tasks is greater than from “pure” nonverbal tasks. A 3 X2X 2 multivariate complete factorial design was employed where Age (5, 8, 12), Input (Visual, Verbal), and Output (Reconstruction, Verbal Description) were main factors. The s’s were 120 children. Forty children each were selected randomly from each of 5-, 8-, and la-year age levels. Ten children from each of the agr groups were assigned randomly lo each of t.he 4 main treatments. Ss were testrd individually. The three main factors and the Age X Output Mode interaction were significant at the .Ol level. The 4 asymptotic estimates of the information output, (channel capacities) of children at any age ranked similarly by treatment. Children’s information output \vas greatest for the “pure” nonverbal task and least for the “pure” verbal task. The verbal loop hypothesis would appear to be c.ontradicted by these data.
Information storage in information-processing tasks may be represented either visually or verbally. Glanzer and Clark’s (1962, 1963, 1964) position is popularly represented by the “verbal loop hypothesis,” that is, Ss process information primarily through a verbal storage and retrieval mode. This hypothesis states that the S processes perceptual information in 2 stages: (1) t ranslation of the input information into words; (2) reproduction of t’he response on the basis of retained verbal information. An implication of the hypothesis is that the length of S’s covert verbalization to a stimulus determines the accuracy of his final response to the stimulus. An estimate of the length of covert verbalization is obtained from the overt, verbalization of the S or that of another S to a stimulus. Furthermore, if the verbal translation of a stimulus is ‘This paper is a revision of the paper prescntcd at the Annual Meeting of the American Educational Research Association, New York, February 4-7, 1971. ‘1 acknowledge with gratitude help and advice given by Dr. D. R. Olson. I am thankful to Dr. T. R. McKague and Dr. H. W. Savage for their comments and suggestions in the revision of this paper. 58 @ 1972 by Academic Press, Inc.
NONVERBAL
INFORMATION
STORAGE
59
available, then recognition will be better than when such verbal translation is absent. The present study was designed to test, this proposition. A second viewpoint (Randhawa 1969, 1970; Rosenfeld 1967) is that nonverbal referents, images, are employed for the storage of information in information processing tasks. Randhawa (1969, 1970) and Rosenfeld (1967) maintain that, the S receives the stimulus via receptor(sj, “organizes” it. via translation, if required, into a nonverbal referent (image) and holds it, and then makes his final response. On the basis of this theory, recognition of a stimulus in nonverbal form (shape, design, pattern, etc.) would be better than that in verbal form. Therefore, this study was designed to test whether the information output from “pure” verbal tasks is greater than from “pure” nonverbal tasks. METHOD
Subjects. The Ss were 120 children in attendance at a suburban junior and senior elementary school. Forty children each were selected randomly from each of 5-, S-, and 12-year age levels. Ten children from each of the age groups were assigned randomly to each of the 4 main treatments. Materink. The basic test materials consisted of a form-board and 32 plastic geometric shapes. All dimensions were binary in variability. The form-board consisted of 8 square slots, 2 at each of the corners as shown in Fig. 1. The form-board contained three dimensional variability, namely, vertical (top or bottom), horizontal (left or right), and color (yellow or blue). Thirty-two (2s) plastic, geometric shapes were evolved from 5 binary dimensions. The shapes varied on form (circle or triangle), color (red
q
green
[3
red
YIC.
1. A
rrl~wscntation
of
the
form-board
60
UIliKAR
8.
RAKDHAWA
or green), size (large or small), line (solid or dotted), and number of centered lines (one or two). A sample of the representations of the shapes is given in Fig. 2. For complete details on t,hese materials consult Randhawa (1969). The plastic shapes were arranged in four adjacent subsets of 8 each in a tray. The 5 dimensions were equiprobable within each set. Since one mode of stimulus presentation was visual, color slides were prepared. Each slide, containing a design of stimulus complexit’y from I-5 bits inclusive, showed a shape on a beige background. However, designs of referent stimullis complexity from 6-8 bits inclusive were shapes emhedtled in onr slot, of the form-board. A referent complexity of x bits means that the S was presented with 2” visual alternatives. Twelve color slides were prepared. Four slides were used as practice materials whose rcfercnt complexities were 2, 4, 6, ant1 8 bits. The remainder of the slides were used in the visuttl task n-here the referent complexities were l-8 bits. Corresponding to catch design and its reference, verbal “messages” were prepared which adequately described for the materials for selection, recognition, etc. For example “Put the object with one solid lint 011 the table” was a verbal message with 2 bits of referent complexity. The correct selection of this object, out of a subyet. of 4 o/ljcrt.s, wa’ possible 011 the basis of line (solid or dotted) and number of centere(l lines (one or twoj. In other words there was only one such object in the ~xposd subset of 4 that had one solid line in the center. similarly @
yellow
:::‘.: I. : :~:,.‘:j,:~,. :;,.:.: .:;...$.:. ::j:.:“-:;:‘:;“i’:,. A
0
blue
NONVERBAL
INFORMATION
STORAGE
61
the verbal message for the g-bit task described all the eight dimensions of the t’esting material, e.g., “Put the small green triangle with 2 dotted lines in the bottom right yellow slot.” The practice slides and verbal messages were presented to all the Ss in order of ascending complexity. However, the experimental slides were presented in a different, randomly selected order for each S. There were ten distinct orders for each visual mode. Corresponding to each written message, a tape recording in a female voice was prepared. All the messages were kept within 5 t 0.5 set in duration. From the first recording another tape was preparctl with the verbal messages arranged in the same ten distinctive orders as for the visual slides. Tusks. The stimulus and the response modes of the four information processing tasks were: (1) Visual (V) input, and Reconstruction (R) output, (2) V input, and Verbal Description (VD) output, (3) Verbal (VL) input, and R output, and (4) VL input’, and VD output. For the V-R and VI,-R treatments, the S was required to reproduce (see below for procedure) the design with the given materials after each presentation of the stimulus. But for the V-VD and VL-VD treatments, the S was required to give a verbal description of t,he design aft,er each presentation of the stimulus in the context, of the reference materials. Design. A 3 X 2 X 2 multivariate factorial design was employed where Age (5, 8, la), Input (V, VL) and Output (R, VD) were main factors. Since all children were shown all the stimuli, the dependent variable, information output, could have been treated as a repeated measure in a univariate design. However, Jones (1966) has illustrat,ed the unique advantage of using a multivariate design since the problem of nesting or confounding of the within-S factor is controlled in a multivariate but not a univariate design.
Procedure In all treatments, t’he S was first acquainted with the shapes and the form-board as the E read the instructions. 1. Instructions for the V-R task. Today we are going to use these objects (show t.he child all the objects) and this form-board (show the child the form-board) or the table to make designs. To make a design you will pick one of these objects and put it in one of the boxes of the form-board or on the table. Before you are asked to make a design, you will be shown the picture of the design on the screen (point to the screen). Look carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly like the design you saw. Are there any questions?
62
13IKhAR
S.
RASDHAWA
But remember, look carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly like t.he design you saw. Shall we begin? 2. Instructions for V-VII task. Today we are going to look at these objects, the table, and this form-board (all the objects and the formboard are shown to the child) to tell all about designs. You will SW a design on the screen and then you wili have to tell all about it. Remember, you are to tell what the object looks like and in which box of the form-board it is placed. In some cases the object. might be placed on the table then you will have to tell this. Speak loudly in the microphone so that what you say can be heard m the other room t,hrough this tape recorder. One of your schoolmates will be making the design on a form-board or on a table with such objects. He cannot see the screen, so you will have to tell him what to do. You should tell him which object to pick and where to put it so that he would make a design exactly like the one you saw. Are there any questions? But remember, you will see a picture on the screen and then you will have t.o teZZ all about it into the tape recorder. Remember you are to tell what the piece loolcs like and where it uu placed. Shall we begin? 3. Instructions for VL-R task. Today we are going to use these objects (show the child all the objects) and this form-board (show the child the form-board) or the table to make designs. To make a design, you will pick one of these objects and put it in one of the boxes of the form-board or on the table. This tape recorder will tell you how to make a design. Listen carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that, it is exactly the design you are told to make. Are there any questions? But remember, listen carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly the design you are told to make. Shall we begin? 4. Instructions for VL-VII) task. Today we are going t.o look at these objects, the table, and this form-board (all the objects, the table, and the form-board are shown to the child) to tell all about designs. You will be told all about a design wit.h this tape-recorder and then you will have to tell all about it. Remember, listen carefully and then tell what the object looks like and where it. was placed. Speak loudly in the microphone so that what you say can be heard in the other room through this tape-recorder. One of your schoolmates will be making the design on a similar form-board or on a table with such objects. He cannot hear what you heard from this tape-recorder, so you will have to tell him what, to do. You should tell him which object to l,ick and where to put it so that he would make a design exactly like
NONVERBAL
INFORMATION
STORAGE
63
the one you could with these objects, the table or the form-board from what you are told with this tape-recorder. Are there any questions? But remember, you will hear about a design from this tape-recorder and then you will have to tell all about it into the tape-recorder. Remember, you are to tell what the piece looks like and where it was placed. Shall we begin? After instructions, 4 practice trials were given in the 4 treatments in the same order to all the Ss. Any questions or misunderstandings of the instructions were clarified and the practice trials were repeated if necessary. In the first treatment (V-R), the S was shown the slides of the designs in a randomly determined order. The slides were projected, individually for 5 set on a screen placed about 10 ft in front of the S. Immediately after this presentation, the E uncovered the reference shapes and the assistant uncovered the form-board if necessary. The S was then required to reconstruct the design, i.e., to pick a shape from the shapes shown and to put it either in one of the form-board slots or on the beige cover of the form-board if the form-board was not involved. In the second treatment (V-VD), the stimuli were presented exactly as in the first treatment. The S began a verbal description of the design when the relevant materials were uncovered. The X was practiced to use the remote control switch on the microphone of the tape recorder. The S was led to believe that his messages were transmitted into another area where one of his schoolmates was to make an identical design, from identical materials, as that seen and described by the S. This prevented the S from simply pointing at the materials and saying “This one in this one”, etc. Without such emphasis and instructions, responses of the above type were evidenced by the researcher in experimental work done previously. Responses were recorded by hand and tape recorder. The stimuli for the third and the fourth treatments were verbal messages recorded in advance in 10 different orders corresponding to the orders of presentation of the visual stimuli. The S in the third treatment (VGR) was required to respond in the reconstruction mode in the same manner as in the V-R treatment after the presentation of the stimulus. In the fourth treatment (VL-VD) the S responded in the description mode in the same manner as in the V-VD t’reatment after the stimulus was presented. Any omissions of the relevant dimensions of the design were counted as errors. ANALYSIS
AND RESULTS
The Ss responses on each trial were converted into scores in bits. An S’s score, in any treatment, was equal to the number of matching relevant dimensions of the test materials contained in the response. For
Example, the S was shown a slide of a small green circle with one solid line through its center. He was asked to choose a shape out of a subset of 4 shapes, in which the 5 dimensions on which the shapes varied were equiprobable. If the S chose a small green triangle with one dotted line through its center, then his score, was zero in bits. This was due to the fact that the subset of shapes had 3 redundant dimensions (attributes). The score in a redundant subset was obtained by using the rule: score = number of matching dimension-redundancy. The score from a nonredundant reference set of materials was equal to the number of matching dimensions. The dependent variable vector of scores corresponding to the stimulus task complexities of 2-8 bits was analyzed using a multivariate analysis of variance (MANOVA) design. The dependent variable element corresponding to stimulus task complexity of one bit was ignored because the within cell variance estimate for this element was zero (all the Ss had perfect scores on this task). Vectors of within variance and means for the main effects (Age, Input Mode, and Output Mode) are given in Table 1. The tests of equality of mean vectors for the main effects and the interactions in the MANOVA design were made using the F-ratios. The rationale for the use of the F-ratios and the computational formulae are provided by Jones (1966). The Age factor was significant (F(14,204) .= 13.26, p < .Ol). The amount of information output was greater for the older children than for the younger children. Visual information processing was easier than verbal as indicated by the significant effect of Input Mode (F(7,102) = 9.86, p < .Ol). The amount of informat.ion output in the reconstruction TABLE 1 VECTOKS OF WITHIN VARIANCE AND MF.ANS (MTS) FOR THE MAIN EFFECTS OF THE INFORMATION OUTPUT
nlain effects Variable bits)
Within variawe
2 3 4
0.23
5
0.68
6 7
1.00
0.30 0.58
1.33 1.71
8 Overall mean
Age (years) 12 1.95 2.97 3.82 4.70
5.15 5.92 6.72 4.46
8 1.95 2.87 3.47 4.12 4.57 5.15 5.67
3.97
Input mode 5 1.22 2.17 2.27 2.82 3.40 3.52 4.20 2.80
Output mode
v
VL
R
VD
1.87 2.67 3.52 4.02 4.87 5.38 5.92 4.03
1.55 2.68 2.87 3.75 3.88 4.35 5.15 3.46
1.73 2.80 3.53 4.50 4.08 6.00 6.82 4.34
1.68 2.55 2.85 3.27 3.77 3.73 4.25 3.16
NONVERBAL
INFORMATION
65
STORAGE
was significantly greater than in verbal description. This was indicated by the significant effect of Output Mode (F(7,102) = 26.94, p < .Ol). The significant Age X Output Mode interaction (F(14,204) = 5.02, p < .Ol) indicated that information output became disproportionately greater with increasing age. However, the verbal input mode was not differentially difficult, for the younger children as opposed to the older ones, as shown by the lack of significant Age X Input Mode interaction (F(14,204) = 1.61, p < .08). To examine the relationship of stimulus complexity and age, the percentage of Ss making perfect responses was plotted in Fig. 3 as a function of stimulus complexit’y for the V-R treatment. For the 5-, 8- and 12-year age groups, as the stimulus complexity increased the task became more difficult. A marked deviation from this trend occurred at 7 bits. However, for the remaining treatments, also, it was observed that the task became more difficult as the stimulus complexity increased (see Figs. 4, Ti and 6).
20
.---p. ..-.-.
i-
1.-
-7
0
-I--
/
2
4 STIMULUS
FIG. 3. Percentages ,Ilwe Age Levels.
of
perfect
12 YR. 8 YR. 5 YR.
-.
performance
I
6
a
(bits)
in
Visual-Reconstruction
‘l’:~sks
RI
66
BIKKAR
0
S. RANDHAWA
-m-++k’T-ii2
STIMULUS
FIG. 4. Percentages at three Age Levels.
of
perfect
performance
(bits)
in
Visual-Verbal
Description
Tasks
The percentages of Ss making perfect responses increased consistently with the increased age for the verbal description output mode. For the reconstruction output mode, the percentages of perfect responses generally increased with the increased age but some slight exceptions occurred as noted in Fig. 3. The asymptot.ic estimates of the information output (channel capacities) of each age group were obtained for each treatment. The 4 channel capacities of children at any age ranked similarly by treatment as indicated in Tables 2-4. The VLVD channel capacity was the smallest while the V-R was the largest one. Thus, children’s information output was greatest, for the LLpure” nonverbal task and least for the “pure” verbal task. The information output for the tasks involving verbal and nonverbal components was between the two extremes. The task involvi~tg verbal output was more difficult than the one involving verbal input. The verbal loop hypotl&:: would appear to be cont,radicted by these
KONVERUAL
IiXFORMATION
STORAGE
67
0 STIMULUS FIG. 5. Percentages three Age Levels.
of perfect
performance
(bits]
in Verbal-Reconstruction
Tasks at
data. However, it is possible that the exact form of the verbal message provided by the experimenter does not match the form in which the object is verbally encoded by the X when seen visually and the selfdirected encoding is probably in a more optimal form for retention and retrieval, visual presentation would be superior to verbal presentation despite verbal encoding. Since the nonverbal information output for the verbally encoded input was much superior to the verbal information output from the visual input, the above objections can be ruled out. Also since the visual input was simultaneous and the verbal message sequential, the output information superiority from visual presentation may be due solely to these differences. It was noted that the nonverbal information output was considerably greater than t,he verbal output when the input for both the tasks was verbal. Thus, the effect of output mode is significant for all ages. The effect of output mode was more dramatic for the visual than for the verbal input. Hence, the superiority of information output from visual as opposed to verbal input may not
68
RIKKAR
S.
RANDHAW.4
IOO-
so-
i :: ;;ii 606 t c f 40-
20-
7~~
7
0
-.7
2
6
4 STIMULUS
FIG. 6. Percentages at three
Age
of
perfect
8
(bits]
performance
in
Verbal-Verbal
Description
Tasks
Levels.
be entirely explained in terms of simultaneous and sequential input differences. These results provide evidence for the untenability and nongeneralizability of the verbal loop theory. How is the proposal of nonverbal storage and retrieval justified? Since the pure nonverbal task was the most efficient, it could be argued that this task involved matching without any translation. The scores of the TABLE
2
CHANNEL C.W.WITY ESTIMATES OF THE 5 YEAR AGE GROUPS FOR THE FOUR TRXZTMENTS (BITS) Input Output
Visual
Reconstruction Verbal description
6.1 2.3
Verbal 5.2 1.7
SONVERBAL
INFORMATION
TABLE CHANNEL
CAPACITY
ESTIMATES
Fount
69
STORAGE
3
OF THE 8 YEAR TREATMENTS (BITS)
AGE:
GIWUPS
FOR
THP:
Input Output
Visual
Verbal
Reconstruct~ion Verbal description
7.2 4.4
5.2 4.2
TABLE CHANNEL
CAPACITY
4
ESTIMATES OF THE 12 YEAI* FOUR TREATMENTS (BITS)
Am GROWS
FOR THE
Input. output
Reconstruct,ion Verbal description
Visual
Verbal
7.5 6.1
7.1 5.4
older children on this task show the least utilization of the cognitive processing space. The pure verbal task on the other hand was the least efficient. The storage and retrieval for t,his task cannot be verbal. For a verbal storage and retrieval, this task would have been a simple matching task requiring a minimum of cognitive processing space. A large amount of cognitive space utilization was probably necessary for this task as indicated by the results. The translation of the verbal input into nonverbal images was needed for perceptual “organization.” This organization was to be stored momentarily and retrieved. The retrieved nonverbal store was to be translated again into verbal response. On the basis of this theory, the mixed mode tasks would require one translation. The verbal input would be translated at input into nonverbal images for storage before the matching response with the retrieved store is made. The visual input would be stored momentarily without any translation. This store would be retrieved and translated into verbal response. Since language acquisition is developmental and since linguistic assimilation precedes linguistic production, the verbal input-nonverbal output task is easier than the nonverbal input-verbal output task. In t,he verbal input task a substantial amount of information is translated into nonverbal form. After the initial translation this task becomes identical to a pure nonverbal task. Very little information loss takes place beyond the translation. In the verbal description output mode restrictive linguistic form development is operative and imposes its 2.
70
BIKKAR
S. RAiVDHAWA
corresponding developmental constraints. Hence the ordering of the mixed mode tasks can be explained on the basis of nonverbal information storage. REFERENCES GLANZER,
M.,
9r CLARK,
W. Verbal loop hypothesis: Conventional figures. American Journcrl of Psycho2ogy, 1964, 77, 621-626. GL.AXZER. M., & CLARK, W. Verbal loop hypothesis: Binary numbers. Jownal oj Iverbal Learning arrd Verbal Behavior, 1963, 2, 301-309. CIAWZER, M.. & CL.~RK, W. Accuracy of perceptual recall: An analysis of organization. Jourrlal of Verbal Learning and Verbal Behavior, 1962, 1, 289-299. JONES. L. V. Analysis of variance in its multivariate developments. In Handbook of multivariate erperime?kxl psychology, R. B. Cattell (Ed.), Chicago: Rand M&ally $ Co., 1966. Pp. 244-266. RAXDHATNA, B. Intellectual development and the ability to process visual and verbal information. Unpublished paper, presented at the Annual Meeting of AERA. Minneapolis : MN, March, 1970. R.~XDHAWA. B. Information processing: A developmental study. Unpublished Ph.D. Dissertat,ion. University of Toronto, 1969. ROSENFELD, J. Information processing: Encoding and decoding. Unpublished Ph.D. Dissertation, Indiana University, 1967.
information
Storage
Developmental Information Channel CapacitylJ BIKKAR University
S.
in Children
and
Processing
RANDHAWA
of Snskatchezca~l,
Saskatoon,
Cnncctla
The present study was designed to test Glnnzcr and Clark’s “verbal loop hypothesis” using children at various developmental levels. In particular, this study attempted to test whether the information output from “pure” verbal tasks is greater than from “pure” nonverbal tasks. A 3 X2X 2 multivariate complete factorial design was employed where Age (5, 8, 12), Input (Visual, Verbal), and Output (Reconstruction, Verbal Description) were main factors. The s’s were 120 children. Forty children each were selected randomly from each of 5-, 8-, and la-year age levels. Ten children from each of the agr groups were assigned randomly lo each of t.he 4 main treatments. Ss were testrd individually. The three main factors and the Age X Output Mode interaction were significant at the .Ol level. The 4 asymptotic estimates of the information output, (channel capacities) of children at any age ranked similarly by treatment. Children’s information output \vas greatest for the “pure” nonverbal task and least for the “pure” verbal task. The verbal loop hypothesis would appear to be c.ontradicted by these data.
Information storage in information-processing tasks may be represented either visually or verbally. Glanzer and Clark’s (1962, 1963, 1964) position is popularly represented by the “verbal loop hypothesis,” that is, Ss process information primarily through a verbal storage and retrieval mode. This hypothesis states that the S processes perceptual information in 2 stages: (1) t ranslation of the input information into words; (2) reproduction of t’he response on the basis of retained verbal information. An implication of the hypothesis is that the length of S’s covert verbalization to a stimulus determines the accuracy of his final response to the stimulus. An estimate of the length of covert verbalization is obtained from the overt, verbalization of the S or that of another S to a stimulus. Furthermore, if the verbal translation of a stimulus is ‘This paper is a revision of the paper prescntcd at the Annual Meeting of the American Educational Research Association, New York, February 4-7, 1971. ‘1 acknowledge with gratitude help and advice given by Dr. D. R. Olson. I am thankful to Dr. T. R. McKague and Dr. H. W. Savage for their comments and suggestions in the revision of this paper. 58 @ 1972 by Academic Press, Inc.
NONVERBAL
INFORMATION
STORAGE
59
available, then recognition will be better than when such verbal translation is absent. The present study was designed to test, this proposition. A second viewpoint (Randhawa 1969, 1970; Rosenfeld 1967) is that nonverbal referents, images, are employed for the storage of information in information processing tasks. Randhawa (1969, 1970) and Rosenfeld (1967) maintain that, the S receives the stimulus via receptor(sj, “organizes” it. via translation, if required, into a nonverbal referent (image) and holds it, and then makes his final response. On the basis of this theory, recognition of a stimulus in nonverbal form (shape, design, pattern, etc.) would be better than that in verbal form. Therefore, this study was designed to test whether the information output from “pure” verbal tasks is greater than from “pure” nonverbal tasks. METHOD
Subjects. The Ss were 120 children in attendance at a suburban junior and senior elementary school. Forty children each were selected randomly from each of 5-, S-, and 12-year age levels. Ten children from each of the age groups were assigned randomly to each of the 4 main treatments. Materink. The basic test materials consisted of a form-board and 32 plastic geometric shapes. All dimensions were binary in variability. The form-board consisted of 8 square slots, 2 at each of the corners as shown in Fig. 1. The form-board contained three dimensional variability, namely, vertical (top or bottom), horizontal (left or right), and color (yellow or blue). Thirty-two (2s) plastic, geometric shapes were evolved from 5 binary dimensions. The shapes varied on form (circle or triangle), color (red
q
green
[3
red
YIC.
1. A
rrl~wscntation
of
the
form-board
60
UIliKAR
8.
RAKDHAWA
or green), size (large or small), line (solid or dotted), and number of centered lines (one or two). A sample of the representations of the shapes is given in Fig. 2. For complete details on t,hese materials consult Randhawa (1969). The plastic shapes were arranged in four adjacent subsets of 8 each in a tray. The 5 dimensions were equiprobable within each set. Since one mode of stimulus presentation was visual, color slides were prepared. Each slide, containing a design of stimulus complexit’y from I-5 bits inclusive, showed a shape on a beige background. However, designs of referent stimullis complexity from 6-8 bits inclusive were shapes emhedtled in onr slot, of the form-board. A referent complexity of x bits means that the S was presented with 2” visual alternatives. Twelve color slides were prepared. Four slides were used as practice materials whose rcfercnt complexities were 2, 4, 6, ant1 8 bits. The remainder of the slides were used in the visuttl task n-here the referent complexities were l-8 bits. Corresponding to catch design and its reference, verbal “messages” were prepared which adequately described for the materials for selection, recognition, etc. For example “Put the object with one solid lint 011 the table” was a verbal message with 2 bits of referent complexity. The correct selection of this object, out of a subyet. of 4 o/ljcrt.s, wa’ possible 011 the basis of line (solid or dotted) and number of centere(l lines (one or twoj. In other words there was only one such object in the ~xposd subset of 4 that had one solid line in the center. similarly @
yellow
:::‘.: I. : :~:,.‘:j,:~,. :;,.:.: .:;...$.:. ::j:.:“-:;:‘:;“i’:,. A
0
blue
NONVERBAL
INFORMATION
STORAGE
61
the verbal message for the g-bit task described all the eight dimensions of the t’esting material, e.g., “Put the small green triangle with 2 dotted lines in the bottom right yellow slot.” The practice slides and verbal messages were presented to all the Ss in order of ascending complexity. However, the experimental slides were presented in a different, randomly selected order for each S. There were ten distinct orders for each visual mode. Corresponding to each written message, a tape recording in a female voice was prepared. All the messages were kept within 5 t 0.5 set in duration. From the first recording another tape was preparctl with the verbal messages arranged in the same ten distinctive orders as for the visual slides. Tusks. The stimulus and the response modes of the four information processing tasks were: (1) Visual (V) input, and Reconstruction (R) output, (2) V input, and Verbal Description (VD) output, (3) Verbal (VL) input, and R output, and (4) VL input’, and VD output. For the V-R and VI,-R treatments, the S was required to reproduce (see below for procedure) the design with the given materials after each presentation of the stimulus. But for the V-VD and VL-VD treatments, the S was required to give a verbal description of t,he design aft,er each presentation of the stimulus in the context, of the reference materials. Design. A 3 X 2 X 2 multivariate factorial design was employed where Age (5, 8, la), Input (V, VL) and Output (R, VD) were main factors. Since all children were shown all the stimuli, the dependent variable, information output, could have been treated as a repeated measure in a univariate design. However, Jones (1966) has illustrat,ed the unique advantage of using a multivariate design since the problem of nesting or confounding of the within-S factor is controlled in a multivariate but not a univariate design.
Procedure In all treatments, t’he S was first acquainted with the shapes and the form-board as the E read the instructions. 1. Instructions for the V-R task. Today we are going to use these objects (show t.he child all the objects) and this form-board (show the child the form-board) or the table to make designs. To make a design you will pick one of these objects and put it in one of the boxes of the form-board or on the table. Before you are asked to make a design, you will be shown the picture of the design on the screen (point to the screen). Look carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly like the design you saw. Are there any questions?
62
13IKhAR
S.
RASDHAWA
But remember, look carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly like t.he design you saw. Shall we begin? 2. Instructions for V-VII task. Today we are going to look at these objects, the table, and this form-board (all the objects and the formboard are shown to the child) to tell all about designs. You will SW a design on the screen and then you wili have to tell all about it. Remember, you are to tell what the object looks like and in which box of the form-board it is placed. In some cases the object. might be placed on the table then you will have to tell this. Speak loudly in the microphone so that what you say can be heard m the other room t,hrough this tape recorder. One of your schoolmates will be making the design on a form-board or on a table with such objects. He cannot see the screen, so you will have to tell him what to do. You should tell him which object to pick and where to put it so that he would make a design exactly like the one you saw. Are there any questions? But remember, you will see a picture on the screen and then you will have t.o teZZ all about it into the tape recorder. Remember you are to tell what the piece loolcs like and where it uu placed. Shall we begin? 3. Instructions for VL-R task. Today we are going to use these objects (show the child all the objects) and this form-board (show the child the form-board) or the table to make designs. To make a design, you will pick one of these objects and put it in one of the boxes of the form-board or on the table. This tape recorder will tell you how to make a design. Listen carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that, it is exactly the design you are told to make. Are there any questions? But remember, listen carefully and then try to pick up the correct piece and put it in the correct box of the form-board or on the table so that it is exactly the design you are told to make. Shall we begin? 4. Instructions for VL-VII) task. Today we are going t.o look at these objects, the table, and this form-board (all the objects, the table, and the form-board are shown to the child) to tell all about designs. You will be told all about a design wit.h this tape-recorder and then you will have to tell all about it. Remember, listen carefully and then tell what the object looks like and where it. was placed. Speak loudly in the microphone so that what you say can be heard in the other room through this tape-recorder. One of your schoolmates will be making the design on a similar form-board or on a table with such objects. He cannot hear what you heard from this tape-recorder, so you will have to tell him what, to do. You should tell him which object to l,ick and where to put it so that he would make a design exactly like
NONVERBAL
INFORMATION
STORAGE
63
the one you could with these objects, the table or the form-board from what you are told with this tape-recorder. Are there any questions? But remember, you will hear about a design from this tape-recorder and then you will have to tell all about it into the tape-recorder. Remember, you are to tell what the piece looks like and where it was placed. Shall we begin? After instructions, 4 practice trials were given in the 4 treatments in the same order to all the Ss. Any questions or misunderstandings of the instructions were clarified and the practice trials were repeated if necessary. In the first treatment (V-R), the S was shown the slides of the designs in a randomly determined order. The slides were projected, individually for 5 set on a screen placed about 10 ft in front of the S. Immediately after this presentation, the E uncovered the reference shapes and the assistant uncovered the form-board if necessary. The S was then required to reconstruct the design, i.e., to pick a shape from the shapes shown and to put it either in one of the form-board slots or on the beige cover of the form-board if the form-board was not involved. In the second treatment (V-VD), the stimuli were presented exactly as in the first treatment. The S began a verbal description of the design when the relevant materials were uncovered. The X was practiced to use the remote control switch on the microphone of the tape recorder. The S was led to believe that his messages were transmitted into another area where one of his schoolmates was to make an identical design, from identical materials, as that seen and described by the S. This prevented the S from simply pointing at the materials and saying “This one in this one”, etc. Without such emphasis and instructions, responses of the above type were evidenced by the researcher in experimental work done previously. Responses were recorded by hand and tape recorder. The stimuli for the third and the fourth treatments were verbal messages recorded in advance in 10 different orders corresponding to the orders of presentation of the visual stimuli. The S in the third treatment (VGR) was required to respond in the reconstruction mode in the same manner as in the V-R treatment after the presentation of the stimulus. In the fourth treatment (VL-VD) the S responded in the description mode in the same manner as in the V-VD t’reatment after the stimulus was presented. Any omissions of the relevant dimensions of the design were counted as errors. ANALYSIS
AND RESULTS
The Ss responses on each trial were converted into scores in bits. An S’s score, in any treatment, was equal to the number of matching relevant dimensions of the test materials contained in the response. For
Example, the S was shown a slide of a small green circle with one solid line through its center. He was asked to choose a shape out of a subset of 4 shapes, in which the 5 dimensions on which the shapes varied were equiprobable. If the S chose a small green triangle with one dotted line through its center, then his score, was zero in bits. This was due to the fact that the subset of shapes had 3 redundant dimensions (attributes). The score in a redundant subset was obtained by using the rule: score = number of matching dimension-redundancy. The score from a nonredundant reference set of materials was equal to the number of matching dimensions. The dependent variable vector of scores corresponding to the stimulus task complexities of 2-8 bits was analyzed using a multivariate analysis of variance (MANOVA) design. The dependent variable element corresponding to stimulus task complexity of one bit was ignored because the within cell variance estimate for this element was zero (all the Ss had perfect scores on this task). Vectors of within variance and means for the main effects (Age, Input Mode, and Output Mode) are given in Table 1. The tests of equality of mean vectors for the main effects and the interactions in the MANOVA design were made using the F-ratios. The rationale for the use of the F-ratios and the computational formulae are provided by Jones (1966). The Age factor was significant (F(14,204) .= 13.26, p < .Ol). The amount of information output was greater for the older children than for the younger children. Visual information processing was easier than verbal as indicated by the significant effect of Input Mode (F(7,102) = 9.86, p < .Ol). The amount of informat.ion output in the reconstruction TABLE 1 VECTOKS OF WITHIN VARIANCE AND MF.ANS (MTS) FOR THE MAIN EFFECTS OF THE INFORMATION OUTPUT
nlain effects Variable bits)
Within variawe
2 3 4
0.23
5
0.68
6 7
1.00
0.30 0.58
1.33 1.71
8 Overall mean
Age (years) 12 1.95 2.97 3.82 4.70
5.15 5.92 6.72 4.46
8 1.95 2.87 3.47 4.12 4.57 5.15 5.67
3.97
Input mode 5 1.22 2.17 2.27 2.82 3.40 3.52 4.20 2.80
Output mode
v
VL
R
VD
1.87 2.67 3.52 4.02 4.87 5.38 5.92 4.03
1.55 2.68 2.87 3.75 3.88 4.35 5.15 3.46
1.73 2.80 3.53 4.50 4.08 6.00 6.82 4.34
1.68 2.55 2.85 3.27 3.77 3.73 4.25 3.16
NONVERBAL
INFORMATION
65
STORAGE
was significantly greater than in verbal description. This was indicated by the significant effect of Output Mode (F(7,102) = 26.94, p < .Ol). The significant Age X Output Mode interaction (F(14,204) = 5.02, p < .Ol) indicated that information output became disproportionately greater with increasing age. However, the verbal input mode was not differentially difficult, for the younger children as opposed to the older ones, as shown by the lack of significant Age X Input Mode interaction (F(14,204) = 1.61, p < .08). To examine the relationship of stimulus complexity and age, the percentage of Ss making perfect responses was plotted in Fig. 3 as a function of stimulus complexit’y for the V-R treatment. For the 5-, 8- and 12-year age groups, as the stimulus complexity increased the task became more difficult. A marked deviation from this trend occurred at 7 bits. However, for the remaining treatments, also, it was observed that the task became more difficult as the stimulus complexity increased (see Figs. 4, Ti and 6).
20
.---p. ..-.-.
i-
1.-
-7
0
-I--
/
2
4 STIMULUS
FIG. 3. Percentages ,Ilwe Age Levels.
of
perfect
12 YR. 8 YR. 5 YR.
-.
performance
I
6
a
(bits)
in
Visual-Reconstruction
‘l’:~sks
RI
66
BIKKAR
0
S. RANDHAWA
-m-++k’T-ii2
STIMULUS
FIG. 4. Percentages at three Age Levels.
of
perfect
performance
(bits)
in
Visual-Verbal
Description
Tasks
The percentages of Ss making perfect responses increased consistently with the increased age for the verbal description output mode. For the reconstruction output mode, the percentages of perfect responses generally increased with the increased age but some slight exceptions occurred as noted in Fig. 3. The asymptot.ic estimates of the information output (channel capacities) of each age group were obtained for each treatment. The 4 channel capacities of children at any age ranked similarly by treatment as indicated in Tables 2-4. The VLVD channel capacity was the smallest while the V-R was the largest one. Thus, children’s information output was greatest, for the LLpure” nonverbal task and least for the “pure” verbal task. The information output for the tasks involving verbal and nonverbal components was between the two extremes. The task involvi~tg verbal output was more difficult than the one involving verbal input. The verbal loop hypotl&:: would appear to be cont,radicted by these
KONVERUAL
IiXFORMATION
STORAGE
67
0 STIMULUS FIG. 5. Percentages three Age Levels.
of perfect
performance
(bits]
in Verbal-Reconstruction
Tasks at
data. However, it is possible that the exact form of the verbal message provided by the experimenter does not match the form in which the object is verbally encoded by the X when seen visually and the selfdirected encoding is probably in a more optimal form for retention and retrieval, visual presentation would be superior to verbal presentation despite verbal encoding. Since the nonverbal information output for the verbally encoded input was much superior to the verbal information output from the visual input, the above objections can be ruled out. Also since the visual input was simultaneous and the verbal message sequential, the output information superiority from visual presentation may be due solely to these differences. It was noted that the nonverbal information output was considerably greater than t,he verbal output when the input for both the tasks was verbal. Thus, the effect of output mode is significant for all ages. The effect of output mode was more dramatic for the visual than for the verbal input. Hence, the superiority of information output from visual as opposed to verbal input may not
68
RIKKAR
S.
RANDHAW.4
IOO-
so-
i :: ;;ii 606 t c f 40-
20-
7~~
7
0
-.7
2
6
4 STIMULUS
FIG. 6. Percentages at three
Age
of
perfect
8
(bits]
performance
in
Verbal-Verbal
Description
Tasks
Levels.
be entirely explained in terms of simultaneous and sequential input differences. These results provide evidence for the untenability and nongeneralizability of the verbal loop theory. How is the proposal of nonverbal storage and retrieval justified? Since the pure nonverbal task was the most efficient, it could be argued that this task involved matching without any translation. The scores of the TABLE
2
CHANNEL C.W.WITY ESTIMATES OF THE 5 YEAR AGE GROUPS FOR THE FOUR TRXZTMENTS (BITS) Input Output
Visual
Reconstruction Verbal description
6.1 2.3
Verbal 5.2 1.7
SONVERBAL
INFORMATION
TABLE CHANNEL
CAPACITY
ESTIMATES
Fount
69
STORAGE
3
OF THE 8 YEAR TREATMENTS (BITS)
AGE:
GIWUPS
FOR
THP:
Input Output
Visual
Verbal
Reconstruct~ion Verbal description
7.2 4.4
5.2 4.2
TABLE CHANNEL
CAPACITY
4
ESTIMATES OF THE 12 YEAI* FOUR TREATMENTS (BITS)
Am GROWS
FOR THE
Input. output
Reconstruct,ion Verbal description
Visual
Verbal
7.5 6.1
7.1 5.4
older children on this task show the least utilization of the cognitive processing space. The pure verbal task on the other hand was the least efficient. The storage and retrieval for t,his task cannot be verbal. For a verbal storage and retrieval, this task would have been a simple matching task requiring a minimum of cognitive processing space. A large amount of cognitive space utilization was probably necessary for this task as indicated by the results. The translation of the verbal input into nonverbal images was needed for perceptual “organization.” This organization was to be stored momentarily and retrieved. The retrieved nonverbal store was to be translated again into verbal response. On the basis of this theory, the mixed mode tasks would require one translation. The verbal input would be translated at input into nonverbal images for storage before the matching response with the retrieved store is made. The visual input would be stored momentarily without any translation. This store would be retrieved and translated into verbal response. Since language acquisition is developmental and since linguistic assimilation precedes linguistic production, the verbal input-nonverbal output task is easier than the nonverbal input-verbal output task. In t,he verbal input task a substantial amount of information is translated into nonverbal form. After the initial translation this task becomes identical to a pure nonverbal task. Very little information loss takes place beyond the translation. In the verbal description output mode restrictive linguistic form development is operative and imposes its 2.
70
BIKKAR
S. RAiVDHAWA
corresponding developmental constraints. Hence the ordering of the mixed mode tasks can be explained on the basis of nonverbal information storage. REFERENCES GLANZER,
M.,
9r CLARK,
W. Verbal loop hypothesis: Conventional figures. American Journcrl of Psycho2ogy, 1964, 77, 621-626. GL.AXZER. M., & CLARK, W. Verbal loop hypothesis: Binary numbers. Jownal oj Iverbal Learning arrd Verbal Behavior, 1963, 2, 301-309. CIAWZER, M.. & CL.~RK, W. Accuracy of perceptual recall: An analysis of organization. Jourrlal of Verbal Learning and Verbal Behavior, 1962, 1, 289-299. JONES. L. V. Analysis of variance in its multivariate developments. In Handbook of multivariate erperime?kxl psychology, R. B. Cattell (Ed.), Chicago: Rand M&ally $ Co., 1966. Pp. 244-266. RAXDHATNA, B. Intellectual development and the ability to process visual and verbal information. Unpublished paper, presented at the Annual Meeting of AERA. Minneapolis : MN, March, 1970. R.~XDHAWA. B. Information processing: A developmental study. Unpublished Ph.D. Dissertat,ion. University of Toronto, 1969. ROSENFELD, J. Information processing: Encoding and decoding. Unpublished Ph.D. Dissertation, Indiana University, 1967.