Conducted 10 experiments to evaluate the notion of" depth of processing" in human memory. Undergraduate Ss were asked questions concerning the physical, phonemic, or semantic characteristics of a long series of words; this initial question phase was followed by an unexpected retention test for the words. It was hypothesized that" deeper"(semantic) questions would take longer to answer and be associated with higher retention of the target words. These ideas were confirmed by the 1st 4 experiments. Exps VX showed (a) it is the qualitative nature of a word's encoding which determines retention, not processing time as such; and (b) retention of words given positive and negative decisions was equalized when the encoding questions were equally salient or congruous for both types of decision. While" depth"(the qualitative nature of the encoding) serves a useful descriptive purpose, results are better described in terms of the degree of elaboration of the encoded trace. Finally, results have implications for an analysis of learning in terms of its constituent encoding operations.(PsycINFO Database Record (c) 2016 APA, all rights reserved)