Questionnaire Development

Question 1

What is Cronbach’s alpha and what is it used for?

Answer 1

It’s a test score reliability coefficient indicating the consistency of items within the same test.

Question 2

What’s the difference between test sensitivity and specificity?

Answer 2

Sensitivity (True Positive Rate) refers to the probability of a positive test, conditioned on truly having the condition

Specificity (True Negative Rate) refers to the probability of a negative test, provided one does not have the condition

Question 3

Initial item pool should not be too inclusive. Yes/No

Answer 3

NO, it should be overinclusive, to enable the sampling of all potential content

Question 4

When selecting items to keep, what are some approaches for deciding?

Answer 4

rational theoretical item selection strategy: items appear consistent with construct to researchers/experts

criterion-keyed item selection strategy: item empirically discriminates individuals with/without construct of interest, e.g. healthy vs. clinical groups

internal consistency approach: items represent homogenous factor(s)

Question 5

What is the goal of factor analysis?

Answer 5

identification of meaningful factors (=subscales) and selection of items with sufficiently high factor loadings