A study was conducted in which 133 participants performed 11 memory tasks (some thought to reflect working memory and some thought to reflect short-term memory), 2 tests of general fluid intelligence, and the Verbal and Quantitative Scholastic Aptitude Tests. Structural equation modeling suggested that short-term and working memories reflect separate but highly related constructs and that many of the tasks used in the literature as working memory tasks reflect a common construct. Working memory shows a strong connection to fluid intelligence, but short-term memory does not. A theory of working memory capacity and general fluid intelligence is proposed: The authors argue that working memory capacity and fluid intelligence reflect the ability to keep a representation active, particularly in the face of interference and distraction. The authors also discuss the relationship of this capability to controlled attention, and the functions of the prefrontal cortex.

The generalized graded unfolding model (GGUM) is developed. This model allows for either binary or graded responses and generalizes previous item response models for unfolding in two useful ways. First, it implements a discrimination parameter that varies across items, which allows items to discriminate among respondents in different ways. Second, the GGUM permits response category threshold parameters to vary across items. A marginal maximum likelihood algorithm is implemented to estimate GGUM item parameters, whereas person parameters are derived from an expected a posteriori technique. The applicability of the GGUM to common attitude testing situations is illustrated with real data on student attitudes toward abortion. Index terms: attitude measurement, generalized graded unfolding model, graded unfolding model, item response theory, Likert scale, marginal maximum likelihood, Thurstone scale, unfolding model.Several researchers have recently argued that binary or graded agree-disagree responses to attitude statements generally result from an ideal point process (Coombs, 1964) in which a person endorses an attitude statement to the extent that it matches the person's opinion (This argument implies that an unfolding (i.e., proximity) model that implements a single-peaked response function would be best for analyzing agree-disagree responses, including both binary and graded responses. In the context of item response theory (IRT), an unfolding model suggests that a person will agree with a statement to the extent that the person and the statement are located near each other on an underlying continuum-a latent continuum that spans the two poles of negative and positive affect.Several unidimensional item response models are available for unfolding agree-disagree responses to attitude statements. Some of these models are appropriate for binary responses, whereas others allow for either binary or graded data. Models for binary data use parametric approaches (Although nonparametric models are practical because they make fewer assumptions about the specific form of the item response function, correctly specified parametric models offer additional measurement advantages. Attitude estimates from parametric models are invariant to the items used to calibrate the estimates. Additionally, estimates of item locations are invariant to the distribution of attitudes in the sample. These two qualities emerge from the fact that if an unfolding model correctly and completely specifies response category probabilities, given only the item and the

The psychometric properties of a children's life satisfaction measure (MSLSS; Huebner, 1994) were assessed with a middle school sample of 291 students. Similar to findings with elementary school students, the MSLSS demonstrated preliminary evidence of reliability and validity for research purposes. The results of confirmatory factor analyses supported the five satisfaction domains identified in previous research with younger students, along with a single higher-order general life satisfaction factor. Relationships among life satisfaction domains, demographic variables, and social desirability responses were discussed. Potential uses of the MSLSS and future research needs were also discussed.

This article highlights the theoretical differences between the Likert and Thurstone approaches to attitude measurement and demonstrates how such differences can lead to discrepant attitude estimates for individuals with the most extreme opinions. Both simulated data and real data on attitude toward abortion are used to demonstrate this discrepancy. The results suggest that attitude researchers should, at the very least, devote more attention to the empirical response characteristics of items on a Likert attitude questionnaire. At most, these results suggest that other methods, such as the Thurstone technique or one of its recently developed item response theory counterparts, should be used to derive attitude estimates from disagree-agree responses.Introductory texts often portray the Thurstone (1928) and the Likert (1932) approaches to attitude measurement as though both methods provide equally valid scores measuring attitude when individuals respond to a set of questionnaire items using a (binary or graded) disagree-agree response scale (Mueller, 1986;Petty & Cacioppo, 1981). This overly simplistic portrayal is fostered by studies that indicate that Likert and Thurstone attitude scores typically are correlated to at least a moderate degree (.60 ≤ r ≤ .95), regardless of whether responses to the same set of items are scored with the two proce-

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