A specially constructed simulated assembly task was used to test the effectiveness of several multichannel communication combinations. The assembly task was a pegboard with a 4 × 4 matrix of ⅓-in. diameter, 3 in. long wooden dowels placed on ⅓-in. centres. Three type3 of wooden washers were made to fit on to the matrix of wooden pegs. The washers were assembled on to the pegs according to a sot of instructions presented to the subject.