The development of a proper survey instrument is often the most concerning aspect of assessing a gain in knowledge or change in behaviors and actions of the program participants.The concerns relate to how to design an effective questionnaire that gathers the information you seek, and has a useful response rate and reliable responses.In exploring these issues, various studies have employed an 11-item AIDS-related knowledge scale (Kalichman and Simbayi, AIDS Care 2-580, 2004) and a 9-item stigma scale (Kalichman et al., AIDS Behav 5-143, 2005), but little evidence exists confirming the psychometric properties of these scales.

Validation data for many of the rounds are available to public users and offer opportunities for studying response variance, item reliability, and other methodological issues.

This is because the workforce changes frequently due to the nature of the production process, the number of sites to be covered, and the use of sub-contract and temporary labour.

The construction industry is also one of the least responsive to the pandemic [].

The selected items are items most respondents will have answered in the main interview and represent a range of expected reliability, including items that are likely to agree between interview and reinterview as well as items that may disagree.

Cases are selected to achieve 10% validation of each interviewer's caseload.