The prediction success table is computed using only probabilities and not estimates based on a threshold value. Using an input table that contains known values for the dependent variable, the sum of the probability values π(x) and 1 – π(x), which correspond to the probability that the predicted value is 1 or 0 respectively, are calculated separately for rows with actual values of 1 and 0. This produces a report table such as that shown below.
|Estimate Response||Estimate Non-Response||Actual Total|
An interesting and useful feature of this table is that it is independent of the threshold value that is used in scoring to determine which probabilities correspond to an estimate of 1 and 0, respectively. This is possible because the entries in the “Estimate Response” column are the sums of the probabilities π(x) that the outcome is 1, summed separately over the rows where the actual outcome is 1 and 0 and then totaled. Similarly, the entries in the “Estimate Non-Response” column are the sums of the probabilities 1 – π(x) that the outcome is 0.