The study was conducted at two New Jersey
locations of a petrochemical research and develop-
ment facility. In 1994, 373 employees responded
``yes'' to a site wide e-mail survey asking whether
they used a VDT for two or more hours a day.
Employees meeting the above criteria were
assumed to be at risk of developing VDT-related
musculoskeletal injuries; these employees were
encouraged to attend a VDT training program
and to complete a self-administered questionnaire
prior to attendance. A total of 292 employees
(79%) completed the baseline self-administered
questionnaire and attended training.
Approximately one year later, the 292 emp-
loyees who had completed the baseline question-
naire and training were asked to complete the
same questionnaire again. A total of 170 of the
original 292 employees (58%) completed both
questionnaires.
For a variety of reasons, the company did not
want to exclude any eligible VDT workers from
the training program. As a result, we could not
randomly select a group of VDT users to not
receive the training (i.e., a control group). Hence,
we utilized a one-group pretest±posttest design, a
design frequently used in non-experimental
research (Cook and Campbell, 1979).