$8-9.$ How does reliability differ from validity? In your answer, define each term.

$8-10.$ What is a questionnaire, and what functions does it serve?

$8-11.$ What is meant by the statement that questionnaire design is a systematic process?

$8-12.$ What are the four guidelines or $"$do$\text{'}s"$ for question wording? Describe each.

$8-13.$ What are the four "don'ts" for question wording? Describe each.

$8-14.$ What is the purpose of a questionnaire introduction, and what should it accomplish?

$8-15.$ Indicate the functions of $($a$)$ screening questions, $($b$)$ warm$-$ups, $($c$)$ transitions, $($d$)$ "skip" questions, and $($e$)$ classification questions.

$8-16.$ What is coding, and why is it used? Relate the special coding requirement with "all that apply" questions.