This study investigated how Information Systems researchers accounted for time in the research design of their studies, as an indication of changing trends in the rigor of IS research. The time period of studies was determined from an analysis of papers published in ten outlets between 1980 and 1996. Of 336 papers found, the 173 empirical papers were classified using a scheme derived from a study by Orlikowski and Baroudi (1991). The papers were classified as ‘one-shot’, ‘multiple snapshot’, ‘longitudinal’ or ‘process trace’, where one- shot papers were regarded as being of low rigor. There were indications that the rigor of the research had generally improved between 1980 and 1996. However, more than a third of empirical papers published between 1992 and 1996 did not account for time in their research design.