Figure 1-4, Confusion Matrix


This is a 2 by 2 table showing actual values (rows) versus 
predicted values (columns). There are two values for each: 
buyers and non-buyers.


The first cell (upper left) is the number of actual buyers 
that were predicted to be buyers. The value entered is 516.


The second cell (upper right) is the number of actual buyers 
that were predicted to be nonbuyers. The value entered is 25.


The third cell (lower left) is the number of actual nonbuyers 
that were predicted to be buyers. The value entered is 10.


The fourth cell (lower right) is the number of actual nonbuyers 
that were predicted to be nonbuyers. The value entered is 725.


This means that the predictions were correct 516 + 725 = 1241 times, 
and incorrect 25 + 10 = 35 times.