4. Methodology
4.1. Sample and procedure
Data were collected through sampling from workers of the New
Zealand construction industry. Approximately 250 workers were
randomly selected and provided questionnaires while they were
attending safety training programs at three different training centers
provided by a national not-for-profit organization. Anonymity
was assured by providing each respondent an addressed envelope
that allowed he/she returned the completed questionnaire to the
researchers. In addition, another 250 questionnaires were administrated
to workers in four construction projects. The procedure of
administration also demonstrated anonymity to respondents by
having them place completed questionnaires in a sealed collection
box. Of 500 questionnaires initially distributed, 215 were completed
and returned. Of those, 213 were sufficiently completed to
be included in data analysis, producing a usable response rate of
43%. Respondent characteristics are shown in Table 1. The sample
size and response rate is comparable with previous safety studies
using structural equation modeling (Cui et al., 2013).
4.2. Survey instrument
The survey consists of three parts: (1) organizational and individual
factors, (2) safety behavior, and (3) demographic information.
Three safety experts reviewed the preliminary survey to
maximize the content validity, as suggested by DeVellis (2003)
and Seo (2005). Included were two safety advisors who both have
had over 20 years of experience of construction safety management,
and a construction safety researcher. Several items were further
refined based on the feedback provided by them.