The purpose of this study, as part of a larger project, was to broach the question of the relationship between interest measures and trade course success. The inventories used as measures of interest were the Kuder Preference Record Form BB, the Miles Short Form of the Kuder (which comprises pages 7, 8 and 9 of the Kuder Form), and the Lee-Thorpe Occupational Interest Inventory Advanced Form A. These tests were administered as part of a battery,which also included measures of intelligence and aptitude, to two groups, one comprising 41 naval writers and the other 157 naval stokers. (1) The relationship between the mechanical and clerical scales was determined by product-moment correlation. The correlations found between the clerical scales were: .53 between the Kuder and the Short Form Kuder, .64 between the Kuder and the Lee-Thorpe, .29 between the Short Form Kuder and the Lee-Thorpe. (2) The correlations found between the mechanical scales were : .80 between the Kuder and the Short Form Kuder, .63 between the Kuder and the Lee-Thorpe , .45 between the Short Form Kuder and the Lee-Thorpe. (3) Product-moment correlation coefficients between the interest scales and the other tests of the battery were very low, ranging from .01 to -.29. (4) Product-moment correlation coefficients between the interest scales and marks obtained In final examinations for the writer and stoker courses were also low, ranging from .11 (between mechanical scale scores on the Short Form Kuder and stokers' course marks) to .24 (between Lee-Thorpe business scale scores and writers' course marks). (5) Multiple correlations, in which measures of intelligence, aptitude and interest scale scores were correlated with course marks, were low, ranging from .23 to .54. These combined measures offered little hope of being useful as a basis for predicting trade course success. (6) Mean scores of writers and stokers were computed and differences between the mean profiles were studied. On 17 of the 29 scales differences were found which were significant beyond the .01 level of confidence. (7) Mean scores for the upper and. lower halves of the writer group (halves being used because of the small number of cases in the sample). No differences were found which were significant to the .01 level, only two being significant at the .05 level. When the same procedure was followed with stoker group scores, differences significant at the .01 level occurred on only two of the scales, two others showing differences significant beyond the .05 level of confidence. In general, the results indicate that prediction of course standing by regression, on the basis of interest scale scores, is not feasible. However, once personnel have been selected as suitable for trade training, the process of allocation can be improved and speeded up by comparing the interest test profiles of the individuals in the group with mean profile patterns for the trades in which training is to be undertaken. / Arts, Faculty of / Psychology, Department of / Graduate

This report presents a review and bibliography of the work which has been done in the fields of manual and mechanical aptitude up to and including July, 1948. All studies in these areas which have been mentioned in the Psychological Abstracts, as well as a number of others which were published prior to 1926, are listed in the bibliography. The more significant of these investigations have been selected for review. The bibliography contains 830 references, of which approximately 500 deal with mechanical aptitude and 300 with manual aptitude. The remaining works listed, while of a more general nature, are studies which have proved useful to investigators in the fields under consideration. Both manual and mechanical aptitudes are discussed with reference to (1) theory, (2) relationships with other traits, (5) development of tests, (4) use of tests in vocational selection, and (5) contributions from European and other countries. British and American theories are compared and contrasted. The relationships between manual and mechanical aptitudes, on the one hand, and such traits as age, sex, and intelligence, on the other, are briefly considered. The subsections entitled "Tests" review the development of various testing procedures. Some attempt has been made to classify these, on the basis of the apparatus used and the type of ability required. Mechanical aptitude tests, for example, may be either performance or pencil and paper tests, and many require one or more of such varied abilities as the accurate perception of spatial relationships, a knowledge of mechanical principles, and the ability to assemble mechanical objects. Most British investigators prefer to consider tests of assembly under the heading of manual dexterity, wherever either the tests or descriptions thereof were available to the reviewer, they have been briefly described. The use of tests of manual and mechanical aptitude for purposes of vocational selection is discussed at some length. It was found that tests have been devised for a vast number of skilled trades, in addition to several of the professions, particularly dentistry and engineering. In the case of mechanical aptitude, tests have been included in guidance as well as in selection programs. Finally, under the fifth heading, an attempt has been made to evaluate the relative contributions of countries other than the United States and Great Britain. The contributions of the countries most prolific in these fields are considered separately. In Europe, until about 1940, Germany led in the number of investigations reported in the Psychological Abstracts, with France and Italy next in line. However, by the beginning of the second world war, Russian studies were becoming quite numerous, and, at present, Russia appears to be approaching the position of dominance once held by Germany. The review terminates with a brief resume under the heading "Summary and Conclusions". It is concluded that adequate studies are still lacking in many areas, and that the principal needs are more careful definition of the jobs studied and the securing of adequate criteria to determine the validity of manual and mechanical aptitude tests. / Arts, Faculty of / Psychology, Department of / Graduate

It was the purpose of this survey to determine what use has been made of psychometric tests in the nursing field and to ascertain how widely this method has been accepted for selection and guidance in the training schools of the United States and Canada. Information regarding the use of tests in the field of nursing in the United States was obtained from the accumulation of literature on the subject and by writing directly to various workers in the field. A detailed survey was made by correspondence of Canadian schools of nursing to determine what use is being made of psychometric tests in the selection of their candidates and the counseling of their trainees. Data were obtained from the Canadian Nurses Association.regarding the rate of withdrawal and the reasons for withdrawal in Canadian training centres. Certain additional information was obtained with regard to the status of testing in English schools of nursing. The collected data were reviewed, analyzed and the salient features noted. The value of psychometric testing to Canadian schools of nursing has been considered. The results of this study regarding the value of psychometic selection methods to Canadian schools of nursing are not conclusive. Although 79% of American schools of nursing employ psychometric selection techniques, the rate of elimination of nursing students in 1947 was 39%. In Canada, where scientific selection methods have been virtually non-existent, the elimination rate was only 20% in 1948. It is doubted that any of the available testing devices could appreciably reduce this figure. It is concluded, however, that testing devices might be used to advantage for the guidance and counseling of nursing students in Canadian training centres and that test batteries might be employed in selection in those areas where the elimination rate appears to be abnormally high. / Arts, Faculty of / Psychology, Department of / Graduate

The purpose of this study was the construction and development of an objective written carpenter's trade test which would represent an economy in the screening of trade applicants. A brief survey was made of the major developments and current trends in the trade testing movement and available pertinent statistics regarding other reported studies was presented. A trade test consisting of two hundred and four items was then constructed. They were multiple choice items and an effort was made to make as many of the items pictorial as was possible. The Canadian Army trade specifications for the trade of carpenter was selected as the subject area which was to be sampled by the test. Material was chosen from existing carpentry tests, technical journals and technical books and incorporated into acceptable items. Each item was reviewed by at least three competent carpenters and evaluated in accordance with the criteria of a good test item before inclusion in the test. The test was then administerd to 240 subjects; 96 novices, 81 apprentices and 63 carpenters. The Wonderlic Personnel Test was administered at the same time in order to obtain an indication of the subject's intelligence. The 204 item test was then scored. The number of items correctly answered by each individual and the percentage of each group answering each item correctly were computed. For each individual item the standard errors of the percentage for each group, the standard error of the difference between the adjacent groups and the "t" ratios were determined. Items for the final test were then selected upon a twofold criteria; these were that a "t" ratio of at least three be obtained between two of the adjacent groups and that not less than fifty percent of the carpenters correctly answered the item and that not more than fifty percent of the novices correctly answered it. One hundred items were selected for the final test. The average "t" ratio between carpenters and apprentices and between novices and apprentices was 3.61. These items were then rescored for each individual. The standard errors of the means for each group, the standard errors of the differences between the means of the adjacent groups and "t" ratios were computed. The resultant "t” ratios were 13.61 between the carpenters and the apprentices groups, 13.55 between apprentices and novices groups and 35.18 between novices and carpenters group. These would indicate very significant differences between the three groups. The reliabilities of the test for each group was determined by the split-half method increased by the Spearman-Brown formula. Reliabilities of .79, .88, .73 and .96 were obtained for the carpenters' apprentices' novices' and total groups respectively. The relationship between trade test scores and other variables was determined. The test showed a statistically significantly reliable, but low, correlation co-efficient with intelligence as measured by the Wonderlic Personnel Test but education, age and experience had a negligible relationship to trade test scores. A reasonable degree of validity was exhibited. The conclusion was drawn that the test would serve a useful adjunct in the screening of trade applicants and that the method followed in its construction could be extended to the development of similar tests for other ocupations. / Arts, Faculty of / Psychology, Department of / Graduate

The problem investigated was the relation of intelligence to the spread of effect. A null hypothesis was set up that the spread pattern obtained from more intelligent subjects would not differ from that found in the less intelligent. Data were collected from two groups of thirty subjects each, one composed of "bright" and the other of "dull" students. All were pupils in Grades V, VI, and VII in the same school. The material was of the conventional type (word-stimulus, number-response) used in many "effect" experiments, but the typical procedure of rewarding correct responses with the announcement "right" and punishing wrong responses with the announcement "wrong" was modified by the omission of the announcement "wrong" during the course of the experiment. Serial position effects were obviated by making successive presentations of the list of stimulus words continuous, and by the length of the list. Favored responses were determined with the help of two presentations free from reward at the beginning of the experiment, and were eliminated from all calculations in order to establish a neutral baseline, which was determined by computing the percentage of total repetitions throughout the five presentations during which rewards were given. Gradients were plotted for each group from the percentages of repetition of rewarded responses and of repetitions one, two, and three steps before and after rewarded responses. The results are such that the null hypothesis must be accepted, that is, intelligence as measured by a standard test is not a variable factor in determining the spread of effect. Of the group differences found, none is statistically reliable. In so far as can be judged from a single experiment and within the parameters of that experiment, it is concluded that reward has equal effect on bright and dull students in a serial learning situation. The relatively low percentage levels of repetition as compared with those of previous studies is attributed to one of two factors, or possibly to a combination of both. In the first place, the method of assembling the data precluded favored responses from contributing to the gradients obtained, and so reduced the number of repetitions calculated. In the second, the word-list was of a length commonly used with subjects at the college level. From these facts, two tentative conclusions are reached. One, that to the extent that favored responses contribute to gradient data, levels of repetition obtained in a number of previous studies and attributed to the effect of reward, are spuriously high, and the influence of reward has been exaggerated. Two, the length of the test (in this case, the word-list), is a factor determining the influence of reward. It is thought that both of these conditions may be responsible, to a degree so far undetermined, for the results obtained in this study. Similarly to the levels of repetition found in each response category, the height of the established base-line is conspicuously lower than any previously adopted, and is noteworthy in its close approximation to the pure chance figure. It has been accounted for on the basis of elimination of favored responses and serial position effects, and would also have been affected by the factor of length of the word-list if this were an experimental variable. A summary consideration of the slope of the gradients from these data compared with gradient curves from previous studies where punishment in the form of the announcement "wrong," as well as reward, was administered to the subjects, revealed no consistent trends and added nothing conclusive by way of evidence on the influence of punishment in a learning situation, other than to emphasize the apparently varying roles this type of "punishment" can play, and the inadvisability of generalizing from the evidence thus far available on its modus operandi. In addition, the fact that unrewarded responses, which were not punished, in seven out of twelve categories were repeated less frequently than consideration of the neutral base-lines would have led one to expect requires explanation. It has been hypothesized that reward, in emphasizing the correct response, acts as a distraction on neighboring connections and thereby reduces their rate of repetition below the chance level. Suggestions were made for further research into the relation of intelligence and extent of spread; into the technique for establishing a base-line; into the factor of favored responses as unduly magnifying the effect of reward; and into the falling off of repetitions of unrewarded though unpunished responses below the obtained chance line. / Education, Faculty of / Graduate

A method for modelling the strength of bonded wood strands which are oriented principally in one direction is proposed. The hypothesis tested was that strand grain orientation data, fitted to a von Mises probability distribution, could be used in an analysis for estimating the potential tensile strength of an ideally bonded composite. The strand strength, resolved at any loading angle with respect to the principal composite strand orientation axis, was multiplied by the distribution probability at that angle. When integrated over all angles, this product yielded the mathematical expectation of strength for the composite. The model predicted composite strength at off-orientation axis angles and represented the material in two dimensions in an orthotropic fashion. A feature of this research is the use of a parametrically quantified strand orientation level in an algorithm developed to estimate composite strength. A practical number of strand angle readings (100) were taken to characterize each composite. These angle readings defined orientation in terms of a parameter which described composites ranging from random to highly oriented. The model input also required microtensile strength means from samples of strands tested in the longitudinal and radial or tangential directions. Comparisons between the model and actual specific strengths were made at five equally spaced-composite principal axis load angles from 0 to 90 degrees. Both tensile and flexural tests were performed to evaluate the model. The evaluations were designated in terms of resin content, distribution, and droplet size. These variables were studied using colorimetry and computerized image analysis. Composite density profiles through the specimens' thickness were obtained from direct reading x-ray densitometry. Composites made of juvenile trembling aspen, red alder, red cedar, mature lodgepole pine and yellow birch were studied. Assumptions concerning wood shear strength and strand length/thickness ratio were discussed in the interpretation of an overlapping strand stress-transfer model. This led to the definition of failure criteria based on stress transfer. A trial of orientation modelling in elasticity estimation was made and a random function model of composite elasticity based on laminated plate theory is outlined in a supplementary proposal for further research. The simplified algorithm for the strength of aligned.wood strand composites provides design targets for reconstituted high strength strand lumber and panel products of the future. / Forestry, Faculty of / Graduate

Perceptual learning was studied using luminous figures in a dark room. It was found that as a result of previous close temporal and spatial concurrence, discriminably different stimuli under reduced stimulation conditions disappear together more frequently than without such an association. This occurred despite a demonstrated link between identical stimuli prior to the learning experience. Moreover it was shown that the extent to which the stimuli subsequently "operated" together was a function of the frequency and duration of their previous joint occurrence. Temporal and spatial stimulus-stimulus relationships were manipulated and differences between sequential and simultaneous presentations and between different presentation rates were observed and discussed. The effect of auditory experience on subsequent disappearances of the same stimuli presented visually was also examined and the results supported the inter-modal perceptual learning hypothesis. The phenomena observed in all these experiments were interpreted in terms of Hebb's theory of perceptual association. / Arts, Faculty of / Psychology, Department of / Graduate

This paper describes how the author studied the "workability" of freshly mixed concrete. Workability is a very important and necessary property which forms part of the specifications for concrete but its meaning is rather vague. Concrete is usually required to have a certain slump or flow, as determined in a standard manner, with standard apparatus, but the readings obtained are comparative only and have no absolute value. The question which the author asks and tries to answer is, can we treat freshly mixed concrete as a fluid and measure its absolute viscosity and if so how are slump and flow etc. related to it? What does slump and flow really mean in terms of absolute units? An apparatus was developed which does measure a quantity similar to viscosity and values were obtained for nine different mixes. Readings were however obtained at only one velocity so that the non-Newtonian behaviour of the concrete was not investigated. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Previous research studies have indicated that coffee brew and water extracts of heated brown food systems such as molasses, beef, prunes and raisins have an inhibitory effect on carcinogen-induced mutagenicity in the Ames Salmonella strains. A hypothesis to explain these observations is that carcinogens are adsorbed onto water-insoluble complexes in coffee brew and melanoidins in heat-treated foods. The present study was undertaken to characterize the water-insoluble fraction (WIF) from reconstituted instant coffee powder; to examine the genotoxic inhibitory effect of the WIF and browning reaction melanoidins; to determine the degree and type of binding of benzo(a)pyrene (BP) and afla-toxin B₁ (AFB₁) by the water-insoluble fraction; and to assess the effect of a model system melanoidin (MSM) on the inhibition of BP induction of aryl hydrocarbon hydroxylase (AHH) in the small intestine of rats. WIF was separated from reconstituted spray dried coffee by precipitation of particulate matter with ethanol at a 90% level and was further purified by resuspension of the precipitate in water and subsequent centrifugal sedimentation. The yield of WIF was about 3% of the instant coffee powder (1.4% moisture). From the non-metallic elemental analysis of WIF, the empirical formula C₄₇H₇₉O₄₁N, was determined. The ratio of C, H, and O atoms suggests the presence of carbohydrates and the nitrogen atom implies the presence of amino acids. The molecular weight of WIF was estimated to be around 200,000 as determined by a column chromatographic technique. A variety of inorganic elements were found in WIF, with potassium in the highest concentration Phenolic compounds, reductones and amino acids were found in WIF. Phenolic compounds were detected by a semiquantitative FeCl₃ colorimetric method which indicated that these compounds were present at a level of 4 mg of caffeic acid equivalent per 10 mg of WIF. The reductone content of WIF was about 140 mg ascorbic acid equivalent per g. Eleven amino acids were identified in the acid hydrolyzate of WIF. The major amino acids were: aspartic acid, glutamic acid, glycine, valine, isoleucine and histidine. Dubois et al. (1956) sugar analysis indicated that 56% of WIF consisted of carbohydrates. Analysis of acid-hydrolyzed WIF by paper chromatography, gas liquid chromatography and GLC-mass spectroscopy indicated that mannose, galactose, glucose and arabinose were the major monosaccharides. Gas liquid chromatography-mass spectrometry showed that the carbohydrates in WIF hydrolyzate were mostly simple hexose sugars with trace amounts of deoxy-sugar fragments, but no N-acetyl glucosamines were identified. The Ames Salmonella test was employed to assess the genotoxic inhibitory effect of coffee WIF and model system melanoidin (MSM) on benzo(a)-pyrene (BP), afiatoxin (AFB₁) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The reverse mutation frequencies were reduced in the presence of WIF and MSM over a range of dosages. Studies were conducted to examine the effect of pH on the binding ability of WIF with BP and AFB₁. A maximum binding of about 83% of BP by WIF in buffer at 37°C was achieved at pH 2.0, and approximately 63% binding of BP by WIF occurred at pH values ranging from 4 to 9. The binding of AFB₁ by WIF in buffers at pH values between 2 to 9 ranged from 47 to 55% at 37°C. A pH effect on afiatoxin B₁ binding to WIF was not apparent. Binding of BP by WIF in citrate buffer (pH 3.0) was examined by column chromatography using different eluants to try to determine the type of binding. The BP peak coincided with the WIF peak when citrate buffer was used (pH 3.0) with and without added NaCl, urea and mercaptoethanol. With SDS added to the citrate buffer eluant, WIF was broken down into smaller particles yet retaining most of the BP. Hydrophobic bonds are presumably involved in the binding of BP to WIF. The activities of aryl hydrocarbon hydroxylase (AHH) in the microsomes of the small intestine of rats fed diets with or without BP and with or without MSM were assessed. The AHH activity for rats on a diet containing both BP and MSM was significantly smaller than that for rats on a diet with BP and no MSM. Components of MSM presumably bind BP to the extent that less BP was available for induction of AHH activity. / Land and Food Systems, Faculty of / Graduate

The purpose of the study was to investigate the effect of specified variation in dilemma content on the relationship among ethical attitude, political attitude, moral development and dilemma action choice. The moral development and action choice scores of individuals who differed in ethical attitude or political attitude were compared for two types of dilemmas, the Defining Issues Test dilemmas and alternate dilemmas, differing in terms of the action supported by authority. Measures of ethical attitude, political attitude and moral development were administered to 68 high school subjects and 35 university subjects. Results of multivariate analysis of variance repeated measures showed that moral development and action choice scores of subjects who differed in ethical attitude or political attitude did not vary for the two dilemma types. Ethical attitude was found to be related to moral development scores for both the Defining Issues Test and Alternate Dilemmas Test, but only to university subjects' action choice scores on the Defining Issues Test. Political attitude was found to be related to only university subjects' action choice scores on the Defining Issues Test. Stepwise regression analysis indicated that the D Index was the best predictor of the Defining Issues Test action choice scores for the high school sample and political attitude was the best predictor for the university sample. Limitations and implications of this research are discussed. / Education, Faculty of / Graduate