In 1985, for the first time, Pennsylvania's student assessment program included measures of a higher order thinking skills goal termed Analytical Thinking. These tests utilize a decision-making model to assess such skills as drawing inferences, identifying appropriate information to gather before making a decision, analogical reasoning, identifying valid arguments against a conclusion, deductive reasoning and drawing overall conclusions. These skills were assessed at grades 5, 8, and 11 in 1985 and at grades 4, 6, 7, 9, and 11 in 1986. In these testings the instruments were found to evidence internal consistency reliabilities ranging from .79 at grade 4 to .86 at grade 11. The results provided evidence of student growth in thinking skills, since higher percentages of older students than younger students were able to answer the same items correctly. These results were consistent across all age levels and skill areas. (Author)