Abstract: This experiment was done with 30 young and 9 middle age subjects on the IBN PC/XT computer. The results showed: (1) The number of fi- gures presented simultaneously, the discrimination time allowed and the age were factors which influenced the subjects'performances. (2) It is not advisable to use middle age persons in discrimination tasks which consist of many figures and which demand high speed response. (3) The experi- ential formula of figure discrimination: Y = De~(B/X); D (N) = 183.1441 - 2. 3206N + 0.0249N~2; B (N) = - 2.0379 0.1427N + 0.0008N~2; was made from the results of this experiment. By using this formula we can obtain a cor- rect discrimination rate for a certain number of figures in a certain ti- me limite.

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