Capillary pulse pressure measurement may have potential as a covert but direct means of determining a subject's level of affect as he encounters the frame-by-frame content of programed instruction. An experiment was designed which called for recording the capillary pulse pressure of subjects as they worked through some programed instruction sequences that had specific flaws deliberately inserted in them. It was hypothesized that the record of capillary pulse pressures would show characteristics which would independently reveal these encounters without the need for further overt interaction with the subjects. Each of the high school students had a small pulse transducer taped to the end of his finger. As he worked through the specially prepared programs, the data obtained was recorded on a chart recorder. It was found that capillary pulse pressure characteristics vary from person to person, but individuals may still be placed in one of a small number of type-groups. Variation in the magnitude of an individual's capillary pulse pressure occurs both as a long term and as a short term phenomenon. It is possible to determine from the charts the level of involvement of a given subject. Samples of charts obtained, statistical charts, tables, and a bibliography supplement the report. (JY)