In man-computer communication, the computer responds only as it is programed to respond. A human's response is more complicated because it depends on the "pre-programed" ways that humans process information. The three functions a man performs on received information are conservation (in which messages are retained whole), reduction (in which messages are condensed), and creation. Each of these functions subsumes several more specific functions labeled transforms. These transforms or sub-functions are described and quantitative measures assigned to them where possible. The area of information conservation includes discussions of short-term memory, veridical memory span, chunking, and proactive inhibition. Transforms relating to reduction are filtering, condensation, and contingent. Information creation involves a one to many mapping of stimuli resulting in output being greater than input. The purpose of the taxonomy and of further research in human information processing is to provide a framework for predicting the speed and efficiency of the performance of various tasks. Such a framework could benefit both the designer of computer software by making possible the generalization of task requirements and the researcher in defining and delineating domains to which his data is applicable. (JK/MT)