Biomedical subjects

John M Linacre

Publications and source records attributed to John M Linacre.

3 recordsLinked to original sources

PubMed2002

Scaling of the revised Oswestry low back pain questionnaire.

OBJECTIVE: To evaluate the measurement properties of the Revised Oswestry Disability Questionnaire (RODQ) by using rating scale analyses. DESIGN: Calibration of item responses by using a data set. SETTING: Four outpatient therapy clinics in the northeastern United States. PATIENTS: Convenience sample of 95 community-dwelling adults exhibiting mild to severe low back pain-related disability (LBP-D). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The RODQ. RESULTS: Several Rasch analyses were performed, with 1 item deleted and 2 response categories collapsed, creating a better test without increased error. A schema for item administration and evaluation was also developed. CONCLUSIONS: By using the abbreviated scale, suggested item order, and predicted responses, abbreviated versions of the instrument can be applied to measure LBP-D more efficiently.

Activities of Daily Living↗

PubMed2002

Optimizing rating scale category effectiveness.

Rating scales are employed as a means of extracting more information out of an item than would be obtained from a mere "yes/no", "right/wrong" or other dichotomy. But does this additional information increase measurement accuracy and precision? Eight guidelines are suggested to aid the analyst in optimizing the manner in which rating scales categories cooperate in order to improve the utility of the resultant measures. Though these guidelines are presented within the context of Rasch analysis, they reflect aspects of rating scale functioning which impact all methods of analysis. The guidelines feature rating-scale-based data such as category frequency, ordering, rating-to-measure inferential coherence, and the quality of the scale from measurement and statistical perspectives. The manner in which the guidelines prompt recategorization or reconceptualization of the rating scale is indicated. Utilization of the guidelines is illustrated through their application to two published data sets.

Data Interpretation, Statistical↗

PubMed2002

Construction of measures from many-facet data.

An extension to the Rasch model for fundamental measurement is described in which there is parameterization not only for examinee ability and item difficulty but also for judge severity. Variants of this model are discussed and judging plans reviewed. Its use and characteristics are explained by an application of the model to an empirical testing situation. A comparison with Generalizability Theory using a common data set is presented as a contrast in approaches to resolving judge indeterminacy.

Calibration↗