Table 1. Effects of Age and Precision on performance.

Modality	Variable	Age	Precision	Age × Precision
sustained	reach time R	F(1,40) = 24.7 p<.001, Δ = 43%	F(1,40) = 45.2 p<.001, Δ = 47%	F(1,40) = 7.0 p<.05
	complete stabilization time S	F(1,40) = 14.8 p<.001, Δ = 35%	F(1,40) = 94.3 p<.001, Δ = 121%	F(1,40) = 3.7 N.S.
	rate of failure F	F(1,40) = 11.1 p<.005, Δ = 107%	F(1,40) = 30.8 p<.001, Δ = 181%	F(1,40) = 7.8 p<.01
impulsion	reach time R	F(1,40) = 7.0 p<.05, Δ = 14%	F(1,40) = 3.9 N.S.	F(1,40) = 0.0 N.S.
	rate of failure F	F(1,40) = 646.9 p<.001, Δ = 48%	F(1,40) = 308.6 p<.001, Δ = 119%	F(1,40) = 2.5 N.S.

Significance threshold is p = .05. Δ = amplitude of effect determined from estimates of marginal means, expressed in percentage of overall Mean.