Abstract Two experiments were designed to further examine the levels of processing analysis of Bloom's taxonomy of the cognitive domain proposed by Kunen, Cohen & Solman (1981). In the first experiment six groups of secondary school students processed 20 principles at the levels of knowledge, comprehension, application, analysis, synthesis and evaluation respectively. The percentages of correctly recalled principle names, were adjusted for the fact that increasingly fewer students successfully completed the taxonomic orienting questions as their level increased from knowledge to evaluation. After adjustment these measures of incidental memory demonstrated a dichotomy of performance, with students who successfully synthesised or evaluated the material being superior. Also recorded in this experiment were measures of working memory and field dependence/independence. These scores proved to be better predictors of student performance on the taxonomic orienting tasks at the higher levels of the taxonomy, and they correctly ordered the levels of analysis, synthesis and evaluation. It was suggested that they provided some independent support for Bloom's contention that the complexity of the cognitive operations required to complete the taxonomic tasks increases with their level. The second experiment manipulated the six taxonomic orienting tasks in a repeated measures design, which required all students to process principles at each of the six levels in order from knowledge to evaluation. While there were minor differences in performance between the Year 7 and the Year 11 students who participated in this study, the adjusted incidental memory data again revealed a performance dichotomy with synthesis and evaluation forming the superior category. That the students demonstrated superior performance after synthesising and evaluating material, was interpreted as support for the continued practice of teaching them to operate at the higher taxonomic levels. This support was qualified, however, by noting that the benefits were confined to those who successfully completed the higher tasks.