Please answer the following question, use own words only please!!!!

1. A researcher decides that the best way to insure a high response rate to a mail survey is to give the respondent $15 on receipt of the returned questionnaire. Is this a good practice to insure responses to the questionnaire?

2. All the questionnaires have gone to the bank's customers only, though stratified in second stage as per area of living. In the first strata only bank customers are being targeted. The data will only apply to these people, whereas it would have been better to have a broader set of people to use. for eg, it is important to include those who don't visit a bank frequently to target them. We are already confining ourselves to a particular set of people who bank.