Which of the following can be used to increase respondent participation?

a. Providing financial incentives or non-monetary rewards such as pens or coupons
b. Telling respondents that they are the sole participants
c. Speaking about the credibility of the organization's management
d. Delivering the questionnaire by mail to ensure minimum contact
e. Providing incentives as rewards

Ans: a. Providing financial incentives or non-monetary rewards such as pens or coupons