The psychometric function: I. Fitting, sampling, and goodness of fit.

The psychometric function relates an observer's performance to an independent variable, usually some physical quantity of a stimulus in a psychophysical task. This paper, together with its companion paper (Wichmann & Hill, 2001), describes an integrated approach to (1) fitting psychometric functions, (2) assessing the goodness of fit, and (3) providing confidence intervals for the function's parameters and other estimates derived from them, for the purposes of hypothesis testing. The present paper deals with the first two topics, describing a constrained maximum-likelihood method of parameter estimation and developing several goodness-of-fit tests. Using Monte Carlo simulations, we deal with two specific difficulties that arise when fitting functions to psychophysical data. First, we note that human observers are prone to stimulus-independent errors (or lapses). We show that failure to account for this can lead to serious biases in estimates of the psychometric function's parameters and illustrate how the problem may be overcome. Second, we note that psychophysical data sets are usually rather small by the standards required by most of the commonly applied statistical tests. We demonstrate the potential errors of applying traditional chi2 methods to psychophysical data and advocate use of Monte Carlo resampling techniques that do not rely on asymptotic theory. We have made available the software to implement our methods.     

The dependent personality: developmental, social, and clinical perspectives.

Developmental, social, and clinical studies of dependency have produced remarkably consistent results. A review and integration of these findings allow strong conclusions to be drawn regarding the etiology and dynamics of dependency. The etiology of dependency appears to lie in overprotective, authoritarian parenting. In social settings, dependency is associated with suggestibility, conformity, compliance, interpersonal yielding, affiliative behavior, and sensitivity to interpersonal cues. Dependency predicts the onset of certain psychological disorders and follows the onset of others. It seems that the fundamental motivation of the dependent person, from which the behaviors that are exhibited in different situations are derived, is a strong desire to obtain and maintain nurturant, supportive relationships. Implications of these findings for different theoretical models of dependency are discussed.     

The perception of self and others: acquaintanceship, affect, and actor-observer differences.

Three studies were designed to examine how people perceive themselves versus others. The main finding was that people were seen as causing positive behaviors, and situational factors were regarded as causing negative behaviors (positivity effect). This positivity effect was found to operate most strongly for perceptions of intimate others, such as spouse and friends, and less strongly for strangers and liked and disliked acquaintances. There was little support for the actor-observer difference that people view their own behavior more situationally than they do other people's behavior. It was concluded that both cognitive and motivational factors must be considered in predicting how people perceive and describe others.     

The locus of adult intelligence: knowledge, abilities, and nonability traits.

Some intelligence theorists (e.g., R. B. Cattell, 1943; D. O. Hebb, 1942) have suggested that knowledge is one aspect of human intelligence that is well preserved or increases during adult development. Very little is known about knowledge structures across different domains or about how individual differences in knowledge relate to other traits. Twenty academic and technology-oriented tests were administered to 135 middle-aged adults. In comparison with younger college students, the middle-aged adults knew more about nearly all of the various knowledge domains. Knowledge was partly predicted by general intelligence, by crystallized abilities, and by personality, interest, and self-concept. Implications of this work are discussed in the context of a developmental theory that focuses on the acquisition and maintenance of intelligence-as-knowledge, as well as the role of knowledge for predicting the vocational and avocational task performance of adults.     

The psychometric function: I. Fitting, sampling, and goodness of fit

The psychometric function relates an observer’s performance to an independent variable, usually some physical quantity of a stimulus in a psychophysical task. This paper, together with its companion paper (Wichmann & Hill, 2001), describes an integrated approach to (1) fitting psychometric functions, (2) assessing the goodness of fit, and (3) providing confidence intervals for the function’s parameters and other estimates derived from them, for the purposes of hypothesis testing. The present paper deals with the first two topics, describing a constrained maximum-likelihood method of parameter estimation and developing several goodness-of-fit tests. Using Monte Carlo simulations, we deal with two specific difficulties that arise when fitting functions to psychophysical data. First, we note that human observers are prone to stimulus-independent errors (orlapses). We show that failure to account for this can lead to serious biases in estimates of the psychometric function’s parameters and illustrate how the problem may be overcome. Second, we note that psychophysical data sets are usually rather small by the standards required by most of the commonly applied statistical tests. We demonstrate the potential errors of applying traditionalX ² methods to psychophysical data and advocate use of Monte Carlo resampling techniques that do not rely on asymptotic theory. We have made available the software to implement our methods.     

The Construction of Mind,Self, and Society: The Social Process Behind G. H. Mead'S Social Psychology

Mind, Self, and Society, the posthumously published volume by which George Herbert Mead is primarily known, poses acute problems of interpretation so long as scholarship does not consider the actual process of its construction. This paper utilizes extensive archival correspondence and notes in order to analyze this process in depth. The analysis demonstrates that the published form of the book is the result of a consequential interpretive process in which social actors manipulated textual documents within given practical constraints over a course of time. The paper contributes to scholarship on Mead by indicating how this process made possible certain understandings of his social psychology and by relocating the materials that make up the single published text within the disparate contexts from which they were originally drawn.