The Sample and Implications for the Analysis
The sample frame consisted of all 5,000 Habo alumni whose email addresses could be assembled by the Habonim Dror office. Nearly 2000 (N=1994 to be exact) eligible respondents returned the survey (a few respondents reported they had not participated in Habonim Dror in their youth, and were dropped from the analysis).
Habonim Dror cannot produce an exact estimate of its alumni, but some observers have arrived at a figure of 40,000 alumni since the first Habonim camps opened in 1935. We must exercise some caution when working with a limited sample frame and sample is that roughly 10% of the total eligible population of those involved since 1960. We have some reason to believe that these are the more connected to Habonim Dror (by virtue of being among the 25% or so appearing on the email lists in the first place) and more committed to Habonim Dror (or its people, its values, etc., by virtue of having been among the 40% who responded to the survey).
To conduct a study of the impact of Habonim Dror in the ideal world, the pristine experimental design would randomly assign Jewish youngsters of similar background to Habonim Dror treatment (or experimental) and control groups. On a random basis, some would be assigned to attend Habonim Dror summer camp, and others would not be assigned to attend. Obviously, in the real world, families who were already more committed to Habonim Dror values, as well as comparable peer groups, guided their youngsters to the Habonim Dror orbit, obviating any possibility of pure random assignment.
But, in addition to self-selection, to an unknown extent, this sample is probably biased in the direction that would demonstrate greater influence of Habonim Dror in the selected outcome areas. Thus, if Habonim Dror is designed to promote Israel commitment and aliyah, then, in all likelihood, this sample contains somewhat more people committed to Israel and more olim than the entire universe of Habos.
That said, by the same reasoning, the intra-sample differences between “heavy” and “light” users of Habonim Dror experience may be less susceptible to sample bias. That is, the gaps in, say, Israel commitment, between those who underwent many Habonim Dror activities over many years as compared with those who undertook just a few activities for a short period may be resilient to the challenges of selective appearance on the email lists or response bias.