Some local dependence was evident, with four items showing positive residual correlations NU7441 ic50 greater than 0.3 in both samples. The items showing positive residual correlations were Item 1 (Demonstrates an understanding
of patient rights and consent), Item 2 (Demonstrates a commitment to learning), Item 3 (Demonstrates ethical, legal and culturally sensitive practice), and Item 5 (Verbal communication). A unidimensional set of items measures a single underlying construct. APP dimensionality was tested by an independent t-test procedure of person ability locations derived from two subsets of items – one loading positively and the other negatively > 0.30 on the first residual factor of the principal components analysis in RUM2020
(Tennant and Pallant 2006). The proportion of persons with significantly different person estimates based on the two item subsets was 7.3% and 6.9% for the two samples. The confidence intervals for a binomial test of proportions both included 5%, providing evidence of the unidimensionality of the scale. Figure 4 shows the relationship between raw ordinal APP scores and person logit location for Sample 1. Sample 2 exhibited the same relationship. This second and final field trial of the 20-item APP confirmed that it is a unidimensional instrument with a response scale that is used as anticipated and that is able to discriminate at least four distinct Selleck Duvelisib levels of student performance. The sequence or hierarchy of average difficulty of the 20 competencies on the APP provides an indication of which clinical competencies may be easier to acquire, such as communication and professional behaviours, and those that are more difficult and therefore may be expected to take longer
to master. The hierarchies of both samples in the current study revealed that items related to analysis and planning (critical thinking), goal setting, and selection and progression of interventions were the most difficult items Etomidate for students to perform. Rheault and Coulson (1991) demonstrated a similar ranking of a 6-item physiotherapy practice assessment instrument. From easiest to most difficult the items were: exhibits professionalism, exhibits communication skills, performs effective treatment skills, performs safe treatment skills, can problem solve, and works from an adequate knowledge base. While the data collected in the field test demonstrated overall fit to the Rasch model for both participant samples, Item 6 (Written communication) showed misfit to the Rasch model. Pallant and Tennant (2007) state that one of the most common sources of item misfit is respondents’ (educators) inconsistent use of the scoring options resulting in disordered thresholds. However, investigation of threshold ordering of the 20 polytomous items on the APP showed there were no disordered thresholds in either sample.