The purpose of this article is to discuss four assumptions commonly held in relation to persistence and or attrition rates at institutions of post secondary education: that persistence is positive, that persistence is an indicator of a program's ability to satisfy student need, that persistence is lower in distance education programs and that comparisons of persistence rates have meaning. The assumptions are explored in relation to the literature and to the data generated by the first complete cohort of graduate students in the Centre for Nursing and Health Studies at Athabasca University. We further propose formulae to address both persistence and attrition in online educational programs and present the variations in rates that can be produced.The literature related to post-secondary education contains abundant opinion and speculation about persistence and attrition rates, particularly in traditional undergraduate classroom situations. With the trend toward more courses being offered through the Internet, more recent research now encompasses persistence