A psychologist wants to describe how often drivers use phones at a busy intersection without interfering. What design best fits that goal?

Students are randomly assigned to drink caffeine or water before a memory test. The researcher wants to know whether caffeine causes a score change. What design is this?

A researcher asks 1,000 students to report their sleep hours and stress level on a questionnaire. What design is being used?

A neuropsychologist studies one patient with a rare memory loss pattern in great depth. What research design is this?

A study measures hours of exercise and mood scores to see whether the two variables move together, with no variable manipulated. What design fits?

A psychologist wants a quick snapshot of many students' self-reported study habits using the same written questions. What method fits best?

Researchers watch preschoolers during free play and record how often they share toys, without changing the classroom routine. What design is this?

A school randomly assigns students to use a mindfulness app or a neutral study app, then compares test-anxiety scores. What design can test cause and effect here?

Runners are given either a sports drink or plain water, and their finishing times are recorded. What is the dependent variable?

One group studies with music and another studies in silence before a math quiz. What is the independent variable?

A sleep study compares teens starting school at 7:30 with teens starting at 9:00, but the later-start group is from a wealthier district. What is the district difference?

In a memory experiment, all students take the test in the same room at the same time of day. What are room and time of day in this design?

In a pain-relief experiment, one group receives an inactive pill that looks like the real medicine. What role does that group play?

A study defines test anxiety as a student's score on a 20-item anxiety scale. What is that definition called?

Teachers are told some randomly chosen students are expected to bloom, and later the teachers rate each student's progress. What is the dependent variable?

Participants study lists of 10, 20, or 30 words before recall is tested. The number of words on the list is what kind of variable?

A researcher uses volunteers from one AP Psychology class to represent all U.S. teenagers. What is the main sampling problem?

A school is 60% ninth graders and 40% tenth graders, and a random sample of 100 includes 60 ninth graders and 40 tenth graders. What strength does this sample have?

An online poll about school start times is open to anyone who chooses to click the link. What bias is most likely?

A survey of adult eating habits is conducted only with shoppers at one mall at 2 p.m. on weekdays. What concern does this raise?

A researcher divides a school by grade level, then randomly selects students from each grade in proportion to its size. What sampling method is being used?

Use the scatterplot of practice hours and quiz scores. Which correlation coefficient best matches the pattern?

Use the scatterplot of screen time and sleep hours. Which coefficient best fits the pattern?

Use the scatterplot of shoe size and vocabulary score. Which coefficient best matches the pattern?

Use the scatterplot of study breaks and focus ratings. Which coefficient is the best estimate?

Use the scatterplot of noise level and reading score. Which coefficient best describes it?

Use the scatterplot of homework completion and course grade. Which coefficient best matches the pattern?

For the data set 2, 4, 4, 6, 9, what is the mean?

For the ordered scores 3, 6, 7, 10, 18, what is the median?

In the scores 4, 5, 5, 6, 6, 6, 8, what is the mode?

A quiz has scores of 72, 80, 84, and 95. What is the range?

Class A scores cluster tightly around the mean, while Class B scores are spread from very low to very high. Which class has the larger standard deviation?

Use the normal curve. A score at the shaded cutoff is roughly what percentile?

Use the histogram of wait times. What shape best describes the distribution?

In a town's income data, a few very high incomes sit far above most households. How does the mean usually compare with the median?

Before a questionnaire, participants are told the study's purpose, possible risks, and that they may quit at any time. Which ethical principle is being followed?

A study temporarily misleads participants about its purpose, then explains the true purpose and why deception was used afterward. What ethical step is this?

Researchers publish participants' names beside their questionnaire answers. Which principle is broken?

A proposed study would expose participants to intense stress without safeguards or a clear need. What ethical concern should reviewers raise first?

Before data collection begins, a committee reviews a study's risks, consent form, and protection of participants. What is this committee's role?