No teacher wishes to be unsuccessful in his instruction but deciding what "successful" means is a problem. One way to describe the degree or lack of success in teaching might be to relate it to changes in learner cognitive structures. Several tools have been developed for investigating such changes. These include P-P (Pretest-Post-test) Graph Analysis and DA (Degree of Adjacency) Analysis, both of which make it easy to visually assess the success of an instructional session. Data for these analyses are obtained from giving the students of the Iwate Form of the Word-Association Test, a simplified version of the word-association tests developed in the United States. Primary findings to date show that there seem to be three patterns of P-P Graphs through which it is possible to assess the degree or lack of success of an instructional segment.