Before instruction, during probe 1, subject A solved none of the problems
correctly using touch points, as indicated in Figure 11. The instructional period for
subject A lasted 10 sessions since she did not meet the criterion of at least 90% correct on
level 8. This level was therefore repeated during the following session. Probes 2, 3 and 4
indicated that subject A remembered the pattern of dots and was able to solve the
addition problems with considerable success. The subject solved an average of 83.3%,
77.8%, and 66.6% of the problems correctly using the touch points on probes 2, 3, and 4
respectively. Over 60% of subject A’s errors during these three probes resulted from
difficulty counting the dots on the number 7. The subject counted nine dots instead of
seven although she employed the dot-notation method successfully. Probe 5 was
administered one and a half months after probe 4 and four and a half months after subject
A completed instruction. Subject A solved an average of 100% problems correctly using
the dot-notation method during the three trials of probe 5.