a gold mine situated twenty miles from Johannesburg. subjects all had at least one tour of duty (a period of

Transcription

1 131 a gold mine situated twenty miles from Johannesburg. The subjects all had at least one tour of duty (a period of six months) on the mines and were thus able to understand Fanakalo which is the lingua franca of the gold mining industry. The tribal composition of the sample was mixed, ts is typical of mine recruits. Information on the age and formal schooling level of the sample will be found in Table 9. Description of the Tests A description of the General Adaptability Battery (G.A.B.) has already been given in the last chapter and will therefore not be described again. The tests below will be referred to as the Conceptual Reasoning 3attery in view of their apparent content. It is hypothesised that they will all have substantial loadings on the dimension or ability labelled Conceptual Reasoning. Form Series Test The Form Series Test (F.S.T.) is an extensive adaptation of Morrisby's (1955) Compound Series Test. This adaptation is described in detail by Grant (1965), The test contains four practice items and eighteen test items. Th. items ar. printed on a sheet of durable paper which is wrapped around a plywood board. This sheet of paper is affixed to th. board by means of double-coated masking tape. Saoh item is e sequel, of symbols! each

2 A 132 symbol being a compound of a particular sisie, colour and shape. In the test, as a whole, three colours, three shapes and two sizes were drawn upon construct the items. The sequence underlying each item was worked out by means of a code. This code enabled the author to /arrange the items in an ascending order of difficulty. Half of the items were of the "in phase*' kind and the other half of the "out of phase" kind. These principles have previously been described by the author. Only part of a sequence i6 presented in each item and the testee is required to contiiue it by affixing two plastic forms, which lie selects from a tray, to the strip of masking tape running down the side of the board. In marking the items of the test, credit is given only if both answer forms are correct in all respects i.e. the shape, colour and size of the two forms all ha'e to bo a correct continuation of the given sequence. The test is untiraed. Xhe S^mbol_Ser^es_i>Te8>t This test was constructed by the author as a simplified version of the Form Series Test with wh*ch it has much ii. common. The Symbol Series Test (S.S.T) contains four practice items and twelve test items. The items are printed on both sides of an 8" x 12" sheet of white cardboard. The symbols in eac*i item were selected from Kellogg s (1967) cross-cultural basic art motifs. These symbols were drawn free-hand in order to avoid the possibility of the subjects trying to reproduce the

3 133 neatness of a printed form. \e in the F.S.T. a sequence of symbols is presented and the subject is required to continue it. He does this by drawing in, with a pencil, two symbols ir. the two spacas provided at th«end of the sequence. As the symbols were cf such a basic nature even illiterates (though they were very shaky at times) had little difficulty in drawing thwra. In marking the test the quality of the drawings vas ignored. Subjects were giv-.1 credit for an item if both spaces were filled in correctly. This test is als. untimed. The Squarss Detection Test (S.D.T.) This test was designed by Hector (1964). It contains one trial sheet and six test sheets. On each shee". a HO mm x UO mm square, with a clearly defined Cot at each corner, is printed in the top left-hand corner. The lest of the sheet is covered with dots which appear, at first glance, to be randomly scattered. The trial sheet contains sixteen dots and each of the test sheets twenty dots. The svtject is required to detect squares, the same size as the model square, from among the scattered dots. Having found a square he connects the four dots by drawing in the lines. There are no irrelevant dots. In test items 1 to 3 the completed squares are apart but they overlap in items ^ to 6. Tne items are made increasingly difficult by gradually bringing th. squares closer together until they overlap.

4 134 The test is untiraad and the score is the total number of squares correctly detected. In a recent, but as yet unpublished study, Peiser and Tekane of the National Institute for Personnel Research throw some light on what the test measures. They intei correlated ail the items of the test and factor analysed the resultant intercorrelation matrix. One of the factors in their unrotated factor natrix was bipolar. The factor loadings of the first three test items were positive and the remaining three negative. This finding suggests that the two groups of items measure different abilities. The first three items probably measure a perceptual Ability while the other three probably measure a conceptual ability. The j^mm«tr _Com letion_te^ (Symco) This test is based on Hector's original PATCO Test (Hector, 19 5b; Fridjohn, 1960; Tekane, 1961 and Tekane, 1963), The test was later renamed the Symmetry Completion Test -r Symco for short. Symco I contains items of a bilateral symmetry kind and Symco II items oi a rotational symmetry kind. Items of a rotational symmetry kind (Symco II) were not included for purposes of this study. All the items used were of a bilateral symmetry kind (Symco I). These items were chosen for thi* study as it was felt that (a) there are elements of bilateral symmetry in both the F.S.T. and the S.S.T. anj (b) as the content of the items is similar to analogies, deductive reasoning would be required to solve them.

5 135 The test version used in the present study contained 6 practice items and 25 test items. Two practice items preceded the first 5 test items *md thereafter each succeeding set of 5 test items w*s preceded by one practice item. In other words a practic? item was done by 'he subject before he went on to deal with each set of test items. The items of the test are printed on the pages of a booklet. Besides the test booklet each subject receives a pencil, a length of straight wire and a black metal oblong which iias a small hole at each Each item of the test appears on a separate page and is made up of one black and two grey oblongs. The oblongs are situated inside a black frame. As given, the item is incomplete i.e. a black oblong is needed to complete the bilatsral symmetry suggested by the other three oblongs. The subject is required to place the metal oblong within the black frame in such a way that bilateral symmetry is achieved. He first finds the symmetry line with the piece oi wire. He then places the metal oblong in position and marks the spot by drawing in the two holes of the metal oblong. The test was untimed. A response was considered correct if the two marks representing the holes in the oblong were ere both within a i> mm radius of the spots representing the correct position of the oblong. 5. The five tests described above were administered by

6 means of demonstration posters which depicted the practice items in an enlarged form. Oral supplements in Fanakalo were also used. Standard test patters were maintained for each testing session and the tests weie administered by two African tasters who were thoroughly trained in the procedure. Procedure The sample was tested at the aptitude testing ceatre of the mine mentioned above. The subjects were first tested on the G.A.B. and then allowed a fifteen-minute break. They were then tested in succession on the Symbol Series, Squares Detection, Symco I and Form Series Tests. The raw scores of the G.A.B. were converted into standard scores and dudecs were calculated. Data on the age and education of the subjects was also collected. Education was expressed as the number of years of school attendance. Statistical A n a l y ^ s and Results. In the analysis of the date which follows all calculations are based on the raw scores except the dudec variable which is a standard score. The means, standard deviations, coefficients of skewness and kurtcsis and observed ranges of the sanple on the G.A.B., th. Conceptual Reasoning Battery and the biographical variables are shown in Table 9.

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8 138 It will be assumed that the sub-tests of the G.A.B. have the same split-half reliabilities as those reported by Biesheuvel (1952). The Kuder-Richardson formula 21 with Tucker's correction (Kuder and Richardson, 1937; Tucker, 1949) was used to calculate the reliabilities of the Symbol Series Test, Symco I and the Form Series Test. The reliabilities are respectively.82,.86 and.92. Ferguson's (1951) extension of the Kuder-Richardson formula 20 was used to calculate the reliability of the Squares Detection Test. It was calculated as.70. All the variables measured were intercorrelated by means of Pearson's product-moment correlation technique. These intercorrelations appear in Table 10. The following variables were excluded from the matrix of intercorrelations which was factored: dudec, age and formal schooling. The reduced matrix appeare in Table 11. The matrix of intercorrelations was subjected to a principal factor analysis. The squared multiple correlations of the variab.es were used for the initial communality estimates and the number of factors to be iterated on -a...tinted by Kai.er'. criterion. Iteration wae continued until the coimunalities converged to a tolerance of.006. Two factor, appeared to be.. _ kjiistr*s decision rule* The significant according to Kaiser s matrix of residuals appears in Table 12.

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12 142 An inspection of the matrix of residuals suggests that two factors were sufficient to account for all the common variance of the tests. The matrix ox orthogonal factor loadings appears in Table 13. The plot of the factors against one another indicated that a rotation of degrees of the original axes would result in a fairly clear structure which is positive manifold. The rotated factor matrix appears in Table 14. A plot of the factors against one another appears in Figure 3. The uniquenosses and specificities of the tests were also calculated. The obtained coefficients are also listed in Table 14, 8. Discussion An inspection of Table 9 shows that the ranges of all the tests wore adequately covered by the sample. Most of the tests tend to be platykurtic, which suggests that they might have high reliabilities (cf. Grant and Schepers). The Symbol Series Test and Cube Construction were a little on the difficult side.whereas the Squares Detection Test was relatively easy. It is suspected that the task involved in the SquaTM Detection Test is intrinsically quite simple. Tc insprove this test a time limit of il minutes per page is suggested.

13 143 TABLE 13 MATRIX OF ORTHOGONAL FACTOR LOADINGS Test I II 1. Sorting I Sorting II Cube Tripod S. Symbol Series Squares Detection Symco Form Series.82.24

14 144 TABLE 14 ROTATED FACTOR MATRIX, COHMUHALITIES Test UNIQUENESSES AND SPECIFICITIES = E F h l ul s2 1. Sorting I c» V*, Sorting II n -.4G Cube Tripod Symbol Series Squares Detection Syraco ? Farm Series

15 rig'jre 3 Conceptual Reasoning and Space : I B. lilatian: S T.i 161/62 r ! C>«ch«4 fcr i _ ^ 0«l«: J N*«* *»*»

16 146 The statistics on dudec, age and education, when compared with those.i,i Grant and Schepers's study and the pilot study on spatial ability, suggest that the sample in this pilot study was drawn from the sane parent population. The reziabilities of the tests in the Conceptual Reasoning Battery are uncommonly high. Except for the Squares Detection Test (.70) all the reliabilities exceed.80. The time limit euggested above would probably result in an improvement of the reliability of the Squares Detection Test. In Table.10 it will be noticed that only Sorting Test II and the Form Series Test correlate significantly at the 5% le''el with age. All other correlations with age are not significant. Educatior. cn the other hand correlates significantly with all the tests except Tripod. It is interesting to note that all the sub-tests of the Conceptual Reasoning Battery correlate significantly with formal schooling. Regarding the Syraco I Test, Reuning and V/ittnann (1963) have observed: "Bilateral symmetry is fundamental in humar cognition and thus, as a test principle, less dependent or. educational achievement..... [than rotational eynmetry]" (p. 89). This is probably true when the two forms of symmetry are compared, but the fact remains that bilateral symmetry is still substantially dependent upon educational achievement. More will be said about the. correlations better, formal s hooling and the tests i +. a l r -er stage.

17 147 The range of correlation coefficients in the reduced matrix (Table 11) ia from.23 to.70 and all', coefficients are positive. On inspectior it would appear that there is more than one factor present among the tests used. The matrix of residuals (Table 12) shows that having extracted two factors the coefficients all approach zero. (The coefficients in the diagonal are uniquenesses). This confirms the Kaiser criterion thac two factors account for all the co.nmon variance of the tests. In the rotated factor matrix (Table 1^), it will be seen that the E' dimsnsion is best defined by the following tests: Form Series, Sorting II, Symbol Series, Sorting I, Symco I and Squares Detection. All the testa in the Conceptual Reasoning Battery hav*. substantial loadings on this dimension, as hypothesized. Both sorting tests also load on this dimension, whic at first glance seem.* surprising. Upon reflection this is not unexpected as will be shown in the ensuing discussion. In all the tests comprising the E' dimension e ulus patterns or compounds of attributes are presented. The first task of the subject is o^e of discrimination. By this is meant that similarities and differences within the stimulus patterns must be perceived and retained. The ability to perceive these similarities or differences, however, does not effect a solution; it is merely a prerequisite to solving the problem. Having accomplished this discrimination task the subject nas to place the

18 Author Grant Gerard Vincent Name of thesis The organization of mental abilities of an African ethnic group in cultural transition PUBLISHER: University of the Witwatersrand, Johannesburg 2013 LEGAL NOTICES: Copyright Notice: All materials on the U n i ve r si t y o f t h e Wi tw a te r s r an d, J o h a n n e sb u rg Lib r a r y website are protected by South African copyright law and may not be distributed, transmitted, displayed, or otherwise published in any format, without the prior written permission of the copyright owner. Disclaimer and Terms of Use: Provided that you maintain all copyright and other notices contained therein, you may download material (one machine readable copy and one print copy per page) for your personal and/or educational non-commercial use only. The University of the Witwatersrand, Johannesburg, is not responsible for any errors or omissions and excludes any and all liability for any errors in or omissions from the information on the Library website.