Model selection strategies play an important, if not explicit, role in quantitative research. The inferential properties of these strategies are largely unknown, therefore, there is little basis for recommending (or avoiding) any particular set of strategies. In this paper, we evaluate several...

Background: A validated productivity questionnaire, the Work Productivity and Activity Impairment questionnaire for Gastroesophageal Reflux Disease (WPAI-GERD), exists for Swedish patients with GERD. Objective: To assess responsiveness to change of the WPAI-GERD and construct validity of the...

Limited availability of irrigation water has placed pressure on farmers and water authorities to improve the efficiency of their operations. ‗Modernisation‘ of irrigation infrastructure systems is occurring throughout Australia in order to improve system delivery efficiency and...

SummaryNearly one tenth (8 per cent) of each cohort of school leavers in Northern Ireland experience long spells of unemployment and inactivity (“Status 0â€) between the ages of 16 and 18. This is important because many such young people are likely to end up unemployed and long-term...

The English version of the WPAI-GERD showed good cross-sectional construct validity, and results indicated that the WPAI-GERD is responsive to change. Although the results also indicated that longitudinal construct validity may be poor, the overall findings suggest that further study of the...