Fig. 2

The crosses (“x”) indicate the scores for subpopulation 0 while the circles (“o”) indicate the scores for subpopulation 1. The averages of the scores for subpopulation 0 for the indicated blocks of observed scores are \(S^0_0\), \(S^0_1\), ..., \(S^0_9\), while the averages of the scores for subpopulation 1 are \(S^1_0\), \(S^1_1\), ..., \(S^1_9\). The averages of the responses for subpopulation 0 corresponding to the indicated blocks of observed scores are \(R^0_0\), \(R^0_1\), ..., \(R^0_9\), while the averages of the responses for subpopulation 1 are \(R^1_0\), \(R^1_1\), ..., \(R^1_9\). The scores need not range from 0 to 1 as in the present figure, but that is a common case