David Eagle's article on changing patterns of religious service attendance appeared in the March 2011 issue of Journal for the Scientific Study of Religion. He presented a comprehensive analysis of three data sets that allow social scientists to estimate the rate of religious service attendance in Canada: Project Canada Survey (PCS), the General Social Survey (GSS), and the Canadian Survey of Giving, Volunteering, and Participating (GSGVP). Reginald Bibby initiated the PCS in 1975, 10 years before Statistics Canada began conducting the GSS in 1985, and 22 years before the GSGVP began in 1997. He comments on the Eagle article, cautions scholars to be mindful of important methodological differences across samples, and offers his own analysis of trends in religious service attendance.