Color matching and shift work: An industrial application of the cusp‐difference equation

This paper considers a practical problem involving a multilevel system: color perception of individual human beings, man‐machine interactions, and changing social factors. Previous research on individuals found a significant but noncritical decline in performance on a color name interference task from noon to 8 p.m. compared to other times of the day. The hypothesis now tested is whether critical diffences in color‐matching efficiency for a group occur over a 24‐hour period. Subjects were 13 color matchers and 30 printers who worked rotating shifts. Data were drawn from production records for 38 pairs of multicolor jobs performed over three four‐week (accounting) periods. Data were analyzed via a cusp catastrophe model for two criteria: color matching time ( R 2 =.99) and printing paper wasted ( R 2 =.98). Job length was the bifurcation factor. Accounting period was the asymmetry factor, which was interpreted in terms of organizational dynamics that were taking place. Thecentral conclusion was that critical differences in color‐matching efficiency could be observed over a 24‐hour period when certain social or task factors are operating.