@article {237, title = {Factor analysis techniques for assessing sufficient unidimensionality of cancer related fatigue}, journal = {Quality of Life Research}, volume = {15}, number = {7}, year = {2006}, note = {0962-9343 (Print)Journal ArticleResearch Support, N.I.H., Extramural}, month = {Sep}, pages = {1179-90}, abstract = {BACKGROUND: Fatigue is the most common unrelieved symptom experienced by people with cancer. The purpose of this study was to examine whether cancer-related fatigue (CRF) can be summarized using a single score, that is, whether CRF is sufficiently unidimensional for measurement approaches that require or assume unidimensionality. We evaluated this question using factor analysis techniques including the theory-driven bi-factor model. METHODS: Five hundred and fifty five cancer patients from the Chicago metropolitan area completed a 72-item fatigue item bank, covering a range of fatigue-related concerns including intensity, frequency and interference with physical, mental, and social activities. Dimensionality was assessed using exploratory and confirmatory factor analysis (CFA) techniques. RESULTS: Exploratory factor analysis (EFA) techniques identified from 1 to 17 factors. The bi-factor model suggested that CRF was sufficiently unidimensional. CONCLUSIONS: CRF can be considered sufficiently unidimensional for applications that require unidimensionality. One such application, item response theory (IRT), will facilitate the development of short-form and computer-adaptive testing. This may further enable practical and accurate clinical assessment of CRF.}, keywords = {*Factor Analysis, Statistical, *Quality of Life, Aged, Chicago, Fatigue/*etiology, Female, Humans, Male, Middle Aged, Neoplasms/*complications, Questionnaires}, author = {Lai, J-S. and Crane, P. K. and Cella, D.} } @article {28, title = {Competency gradient for child-parent centers}, journal = {Journal of Outcomes Measurement}, volume = {3}, number = {1}, year = {1999}, note = {1090-655X (Print)Journal ArticleResearch Support, U.S. Gov{\textquoteright}t, P.H.S.}, pages = {35-52}, abstract = {This report describes an implementation of the Rasch model during the longitudinal evaluation of a federally-funded early childhood preschool intervention program. An item bank is described for operationally defining a psychosocial construct called community life-skills competency, an expected teenage outcome of the preschool intervention. This analysis examined the position of teenage students on this scale structure, and investigated a pattern of cognitive operations necessary for students to pass community life-skills test items. Then this scale structure was correlated with nationally standardized reading and math achievement scores, teacher ratings, and school records to assess its validity as a measure of the community-related outcome goal for this intervention. The results show a functional relationship between years of early intervention and magnitude of effect on the life-skills competency variable.}, keywords = {*Models, Statistical, Activities of Daily Living/classification/psychology, Adolescent, Chicago, Child, Child, Preschool, Early Intervention (Education)/*statistics \& numerical data, Female, Follow-Up Studies, Humans, Male, Outcome and Process Assessment (Health Care)/*statistics \& numerical data}, author = {Bezruczko, N.} }