On rotating to smooth functions

Tucker has outlined an application of principal components analysis to a set of learning curves, for the purpose of identifying meaningful dimensions of individual differences in learning tasks. Since the principal components are defined in terms of a statistical criterion (maximum variance accounted for) rather than a substantive one, it is typically desirable to rotate the components to a more interpretable orientation. Simple structure is not a particularly appealing consideration for such a rotation; it is more reasonable to believe that any meaningful factor should form a (locally) smooth curve when the component loadings are plotted against trial number. Accordingly, this paper develops a procedure for transforming an arbitrary set of component reference curves to a new set which are mutually orthogonal and, subject to orthogonality, are as smooth as possible in a well defined (least squares) sense. Potential applications to learning data, electrophysiological responses, and growth data are indicated.Portions of this research were supported by the National Research Council of Canada, Grant A8615 to the second author. We thank Jagdeth Sheth for supplying his raw data.     

Classifying pictures and words: Implications for the dual-coding hypothesis

In deciding that two items come from the same category, subjects were delayed if the items were presented as a word and a picture, as compared with two words or two pictures. Subjects were not delayed if the items were not to be compared. Hence, the delay appears to occur during the retrieval and comparison of know ledge about the items, not during their perceptual analysis. The results suggest that there are two distinct codes involved in the categorization of words and pictures, rather than a single code.     

A view of the background of Freudian theory.

A major concern of nineteenth century scientists was to delineate the objective units or entities with which science deals. While some philosophers of science abandoned the search as futile and tried to redefine science, investigators in the biological sciences and the sciences of man attempted to discover new entities upon which to base their disciplines. A new understanding of hypnotism gave Freud the opportunity to isolate objective entities within the mind and to found a psychology on that basis.     

A defense of the use of metaphor in analytic theory formation.

This study of psychoanalytic theory formation is based on the epistemology of Cassirer and Langer. It postulates the need of all sciences to operate with symbols of various levels of abstractions, including, in a very prominent way, metaphors. There is not just one scientific method. The current wave of criticism against psychoanalytic theory from within and without, and especially of its use of metaphor in theory formation, is based on a philosophy of radical empiricism which cannot do justice to the science of psychoanalysis.     

A note on the estimation of the level of predictive precision of a fitted linear equation

A procedure that utilizes the sample multiple correlation to form a lower bound for the level of predictive precision of a fitted regression equation is suggested. The procedure is shown to yield probability statements which are true at least 100(1–)% of the time.     

Book reviews

Hamilton, Vernon and Veronon, Magdalen D. (Eds). The Development of Cognitive Processes. London and New York: Academic Press. 1976. Pp. 772. £21.00. ISBN 0 12 321750 4.

Miller, G. A, and Johnson-Laird, P. N. Language and Perception. Cambridge University Press. 1976. Pp. viii + 760. £12.50. ISBN 0 521 21242.

Neisser, U. Cognition and Reality. San Francisco: Freeman. 1976. pp. 230. Hardback $11.00; paperback $4.95. ISBN 0 7167 04781.

Norman, D. A. Memory and Attention. Second edition. New York: Wiley. 1976. Pp. 262. £8.45.

Hammond, K. R. and Joyce, C. R. B. (eds). Psychoactive Drugs and Social Judgment: Theory and Research. New York and London: Wiley. 1975. Pp. 278. £9.25. ISBN

Fodor, J. D. Semantics : Theories of Meaning in Generative Grammer. Sussex: Harvester Press. 1977. Pp. 225. £12.95. ISBN 0 85527 500 6.

Plomp, R. Aspects of Tone Sensation. London: Academic Press. 1976. Pp. id + 167. £6.50. ISBN 0 12 558350 8.

Fite, K. V. The Amphibian Visual System. London: Academic Press. 1977. Pp. 374. £20.95. ISBN 0 12 257450 8.

Eliot, J. and Salkind, N. J. Children's Spatial Development. Springfield, Illinois: Charles C. Thomas. 1975. $23.50. Pp. 296. ISBN 0398 03210 6.

Wong, R. Motiviation : A Biobehavioral Analysis of consummatory Activities. London: Collier-Macmillan. 1976. Pp. 326. £ 4.95. ISBN 0 0242 9400 4.