Workers involved in the study were hired at a .

In spite of some obvious differences between groups of workers, the survey was statistically .

The speaker analysed the study’s  to identify any problems with it.

The various subgroups were  in size.

Workers in the part-time group were mainly .

The  of workers who agreed to take part in the study was disappointing.

Researchers were unable to  the circumstances where employees filled out the questionnaire.

In future, the overall size of the  should be increased.

In the studies, workers should be prevented from having discussions with .

Workers should be reassured that their responses to questions are .