The Wisconsin Longitudinal Study (WLS) is a longitudinal population cohort started in 1957, with a questionnaire administered to all Wisconsin High School seniors. In 1964, a randomly selected one-third of the members of the class of 1957 were followed up with a brief questionnaire to parents asking about their child’s post high-school education and occupation. Direct contact with the graduate began with a telephone interview in 1975, and subsequent telephone and mail surveys in 1993 2004. In 1977 a subset of graduate’s siblings were interviewed by phone and in 1995 and 2005 interviews were conducted with one sibling from each family whenever possible. Spouses of Graduates and Siblings who were married at the time of the 2004/2005 interview were also interviewed by phone. Most recently in-person interviews with a leave-behind questionnaire were administered in 2011 to both the graduate and sibling panels. Saliva was collected from both graduate and sibling participants via a mail-effort in 2008 and during the in-person 2011 interview.

Last Update 21/09/2017