a)Identify the sampling frame.

b)identify the sample and its size.

c)Is the sampling frame the same as the population of interest? explain.

d)name and briefly describe sampling method used in this study. If this is multistage, write on what these stages are.

e) the writer says that a telephone interview was used in data collection & this strategy is not likely to cause systemic bias. do you agree or not? explain.

At the time of recruitment for the study, 61,000 students were enrolled in a 2ndary school in canadian state of toronto. 40 schools were selected randomly, & then 2 class were selected at random from each of the 40 school. All 20,000 students in selected classes completed baseline questionnaires. Students were followed up for several years & only 1,500 students completed the follow up questionaire of end of study. What is the sampling frame