In a series of two studies, we graphed simulated data representing continuous duration recording and continuous frequency recording into ABAB reversal designs depicting small, moderate, and large behavior changes during 10-min, 30-min, and 60-min sessions. Data sets were re-scored using partial-interval recording and momentary time sampling with interval sizes set at 10 s, 20 s, 30 s, 1 min, and 2 min. In study 1, we visually inspected converted data for experimental control and compared the conclusion with those from the respective continuous duration recording or continuous frequency recording data to test for false negatives. In study 2, we evaluated the extent to which interval methods that were sensitive to changes in study 1 produced false positives. In part, the results show that momentary time sampling with interval sizes up to 30 s detected a wide range of changes in duration events and frequency events during lengthier observation periods. The practical implications of the findings are briefly discussed. Copyright © 2011 John Wiley & Sons, Ltd.