FIGURE 4.

Task performance and control rating as functions of noise level. Task performance (distance to target in a pixel-based unit) (A) and sense of control rating (B) plotted as functions of noise level for all groups. Group 1 (black) consisted of participants using scales with fewer than six steps, group 2 consisted of participants using a 6-point scale, and group 3 consisted of participants using scales with more than 6-points. For groups 1 and 3, the ratings were transformed to fit an interval scale from 1 to 6 to ensure comparability between groups. Four-parameter sigmoid functions were fitted to the data.