An additional factor in the design

An additional factor in the design will be repeated measurement of outcomes per apprentice on four occasions: 1) At baseline, 2) Post primary training for each group, 3) 6 months following primary training, and 4) 12 months following primary training. The resulting overall design will be a 2 x 2 x 4, Ergonomic Training by Safety Voice Training by Time of Measurement factorial design with repeated measures on the last factor and apprentices nested within training centers.