A conditional logit model of collegiate major selection

The choice of a major by a college student is viewed as depending upon the quantity of various outputs (such as income and status) each major provides and the taste structure of the student for these outputs. Tradeoffs in outputs occur so that high status may overcome low-income potential in the occupation into which the major provides entry. Different taste structures among students mean tradeoffs occur at different rates, so that taste structues are best associated with student major selection in a probability sense. Changes in the probability of selecting a collegiate major are associated with changes in student taste structures via a conditional logit model. The taste structure of a student is hypothesized to depend upon the environment in which the student was raised and the environment in which the student now lives. The relationship between environment and taste is also best stated in a probability sense and a second logit model is used to describe this relationship. Estimation of the two logit models, using survey data, attempts to quantify the hypothesized route from environment to taste structure to major selection for entry into an occupation. An example of this route is the finding that women students place more importance on obtaining high income than do men students and the greater the importance of high income, the lower the probability of selecting an education major, the greater the probability of selecting a humanities or social science major. Other results of estimation are presented and discussed.     

An approach to geometry of visual space with no a priori mapping functions: Multidimensional mapping according to Riemannian metrics

A method of multidimensional mapping is described which constructs a configuration of points {P_i} in a Euclidean map of Riemannian space of constant curvature (hyperbolic, Euclidean, and elliptic) from the dissimilarity matrix (d_ij). The method was applied to the distance matrix in visual space where stimulus points Q_i were either small light points in the dark or small black points in the illuminated field surrounded by white curtains and d_ij represent scaled values of perceptual distances. Configuration of points {Q_i} were at intersections of parallel or distance alleys and horopters for the subject in the horizontal plane of the eye level. In contrast to the theoretical equations for {Q_i} by Luneburg and Blank, no a priori assumption on mapping functions between {Q_i} and {P_i} is necessary in this procedure to fit theoretical curves to {P_i} in the Euclidean map. The data were accounted for better by equations in the hyperbolic plane than by ones in the Euclidean plane. Discussions are made on robustness of Euclidean representation and on how to approach geometry of visual space as a dynamic entity under more natural conditions than the traditional frameless condition for alley and horopter experiments.     

An experimental and theoretical investigation of the constant-ratio rule and other models of visual letter confusion

The constant-ratio rule (CRR) and four interpretations of R. D. Luce's (In R. D. Luce, R. R. Bush, & E. Galanter (Eds.), Handbook of mathematical psychology (Vol. 1). New York: Wiley, 1963) similarity choice model (SCM) were tested using an alphabetic confusion paradigm. Four stimulus conditions were employed that varied in set size (three, four or five stimulus elements) and set constituency (block letters: A, E, X; F, H, X; A, E, F, H; A, E, F, H, X), and were presented to each subject in independent blocks. The four interpretations of the SCM were generated by constraining one, both, or neither of its similarity and bias parameter sets to be invariant in across-stimulus set model predictions. The strictest interpretation of the SCM (both the similarity and bias parameters constrained), shown to be a special case of the CRR, and the CRR produced nearly equivalent across-set predictions that provided a reasonable first approximation to the data. However, they proved inferior to the least strict SCM (neither the similarity nor bias parameters were constrained; the common interpretation of the SCM in visual confusion). Additionally, the least strict SCM was compared to J. T. Townsend's (Perception and Psychophysics, 1971, 9, 40–50, 449–454) overlap model, the all-or-none model (J. T. Townsend, Journal of Mathematical Psychology, 1978, 18, 25–38), and a modified version of L. H. Nakatani's (Journal of Mathematical Psychology, 1972, 9, 104–127) confusion-choice model. Both the least strict SCM and confusion-choice models produced nearly equivalent within stimulus set predictions that were superior to the overlap and all-or-none within-set predictions. Measurement conditions related to model structure and equivalence relations among the models, many of them new, were examined and compared with the statistical fit results of the investigation.     

The acquisition of prenominal modifier sequences

This paper presents a study of children's interpretations of prenominal modifier sequences like the one in ‘the second green ball’. In such phrases the modifier ‘second’ has scope over the rest of the phrase. It is shown that children misinterpret these phrases in such a way that it appears that they give ‘second’ scope only over the head noun of the phrase. A series of six experiments, all designed to test various hypotheses about the motivating factors behind this misinterpretation is described. Experiments 1 and 2 constitute a replication and extension of the work in this area originally done by Roeper (1972). Experiment 3 tests a set of hypotheses about the influence of certain syntactic variables in conditioning the children's misinterpretations. Experiment 4 is an attempt to check an hypothesis about the semantic complexity of phrases like ‘the second green ball’. Experiments 5 and 6 test the children's sensitivity to ordering constraints in different kinds of prenominal modifier sequences. The results are presented in Section 3 and discussed in Section 4. It is argued that the children's misinterpretations of the phrases come about because of their tendency to be conservative about the amount of hierarchically organized structure they will postulate in the absence of evidence that such structure is needed.     

Automatic access of the meanings of ambiguous words in context: Some limitations of knowledge-based processing

Five experiments are described on the processing of ambiguous words in sentences. Two classes of ambiguous words (noun-noun and noun-verb) and two types of context (priming and nonpriming) were investigated using a variable stimulus onset asynchrony (SOA) priming paradigm. Noun-noun ambiguities have two semantically unrelated readings that are nouns (e.g., PEN, ORGAN); noun-verb ambiguities have both noun and verb readings that are unrelated (e.g., TIRE, WATCH). Priming contexts contain a word highly semantically or associatively related to one meaning of the ambiguous word; nonpriming contexts favor one meaning of the word through other types of information (e.g., syntactic or pragmatic). In nonpriming contexts, subjects consistently access multiple meanings of words and select one reading within 200 msec. Lexical priming differentially affects the processing of subsequent noun-noun and noun-verb ambiguities, yielding selective access of meaning only in the former case. The results suggest that meaning access is an automatic process which is unaffected by knowledge-based (“top-down”) processing. Whether selective or multiple access of meaning is observed largely depends on the structure of the ambiguous word, not the nature of the context.     

Lateral asymmetries in the naming of words and corresponding line drawings

Laterally displaced line drawings and the words which name these drawings were tachistoscopically presented to adult subjects. For words, as expected, a right visual field-left hemisphere advantage was obtained. For line drawings, in contrast to previous studies which have typically reported a right visual field-left hemisphere advantage, no visual field asymmetry was found. The absence of a visual field asymmetry for line drawings is consistent with reports of a shift toward greater right hemisphere involvement in the recognition of pictographic as compared to phonetic writing systems and concrete/imageable words as compared to abstract/nonimageable words. Further, the present results seem consistent with findings on picture recognition and naming abilities in brain-damaged patients.