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A readily and widely applicable procedure is discussed that can be used to point and interval estimate the probabilities of particular responses on polytomous items at pre-specified points along underlying latent continua. The items are assumed thereby to be part of unidimensional multi-component measuring instruments that may contain also binary and/or other polytomous items as well as following the popular graded response model, possibly within hybrid item response models. The approach generalizes extant research on estimation of the probability for a specific response on a binary or binary scored item at latent locations to the polytomous item case. The method can be used for answering theoretically and empirically relevant questions concerning given response probabilities on pre-specified items, such as Likert-type questions within surveys or questionnaires, at certain distances from the latent population mean. The discussed procedure is directly employed with widely circulated statistical software and is illustrated using an empirical example.

It is demonstrated that the popular three-parameter logistic model can lead to markedly inaccurate individual ability level estimates for mixture populations. A theoretically and empirically important setting is initially considered where (a) in one of two subpopulations (latent classes) the two-parameter logistic model holds for each item in a measuring instrument, while (b) this model as well as the three-parameter logistic model for an item with guessing are valid for the instrument in the second class. Fitting the respective hybrid models then to the overall data set, with the three-parameter logistic model assumed for that item, is found to lead to notably inaccurate individual trait score estimates in either class. The implications of the reported results for contemporary empirical educational and behavioral research are finally discussed.

Introduction: Associations across self-efficacy, social support, and multiple measures of physical activity (PA) have not been thoroughly explored in hospital employees. Methods: Validated surveys assessed psychosocial factors; the IPAQ-long assessed PA, and mixed-effects analyses examined relations between psychosocial variables and PA in 920 employees from 6 Texas hospitals. Results: At P <.05, self-efficacy was significantly associated with light (β = 1.67), moderate (β = 1.63), and vigorous (β = 2.78) leisure PA; with domestic PA (β = 1.64); and with moderate commute PA (β = 0.03). At P <.05, family social-support was significantly associated with light (β = 0.94), moderate (β = 0.63), and vigorous (β =.74) leisure PA; with moderate (β = 0.46) and vigorous (β = 1.24) occupation PA; with light (β = 0.58) and moderate (β = 0.20) commute PA; and with domestic PA (β = 1.18). At P <.05, social support from friends was significantly associated with light (β = 0.74), moderate (β = 0.58), and vigorous (β =.91) leisure PA; with moderate commute (β = 0.21); and with domestic PA (β = 0.82). Conclusion: Interventions must emphasize self-efficacy–building strategies and the role of family support to meaningfully impact PA behaviors in uniquethis unique population. [ABSTRACT FROM AUTHOR]

Discusses proposals for more standardized practices in CD-ROM development, sales, and distribution. Topics discussed include availability of trial copies; pricing policies; installation, including software, instructions, and compatibility; interface procedures; manuals; and vendor support services. A sidebar discusses proposals being addressed by a committee of the National Information Standards Organization (NISO). (LRW)

Presents an overview of the different sessions held at the 2005 Annual Special Libraries Association Conference held in Toronto, Ontario. Academic librarians roundtable; Systems thinking for librarians; Computer science roundtable.