From a distance a "C" may appear to be an "O." This is an example of which Gestalt law?

A key difference between operant and classical conditioning is that in classical conditioning a response is not required for a reward (or unconditioned stimulus) to be presented

Indicate whether this statement is true or false.

A researcher interested in studying how friendship changes with age asks students in first-, third-, fifth-, seventh-, ninth-, and eleventh-grades to complete a questionnaire. What type of research design is this researcher using?

a. sequential-cohort b. longitudinal c. cross-sectional d. age cohort