The Mechanical Disturbance Produced by Steady and Gusty Winds of Moderate Strength: Skilled Performance and Semantic Assessments

Abstract

Two groups of 11 women were filmed walking into a wind tunnel with inked pads on the soles of their foet. They also attempted to walk on their own footmarks, and performed a number of other tasks in the wind. Afterwards they made semantic assessments. The wind was either 4 or 85 m/sec (force 2 to 3 or 4 to 5 on the Baufort wind scale), with 05 or 12% turbulence. Each group of volunteers received both levels of turbulence at a single windspeed, order being balanced over the group. Increases in both windspeed and turbulence reliably degraded performances on most of the tasks. The women were blown off course- on first entering the wind and sometimes lost their balance for a moment. Adding the 12% turbulence to the low windspeed of 4 m/sec was almost as detrimental as increasing the windspeod to 8-5 m/sec. The semantic assessments paralleled the measures of performance. However the correlations between individual women's performances and their corresponding semantic assessments were not different from chance. This suggests that the semantic assessments wore based upon what the women thought ought to happen, rather than upon what did actually happen. Two semantic assessments showed reliable asymmetrical transfer between the first and second conditions. None of the measures of performance did so. The asymmetrical transfer invalidates the semantic assessments of the conditions performed second.