In an experiment, what is the independent variable?

Students sleep 6, 7, or 8 hours before taking a reaction-time test. What is the independent variable?

A teacher gives one class praise after each quiz and gives another class no comments, then compares homework completion. What is the independent variable?

A study tests whether using a mindfulness app daily or not using it affects stress ratings. What is the independent variable?

In an experiment, what is the dependent variable?

A researcher changes the font size of a passage and then records each student's quiz score. What is the dependent variable?

Volunteers walk for 20 minutes or sit quietly, then rate their mood from 1 to 10. What is the dependent variable?

Participants hear ocean sounds or silence while sleeping, and a tracker records how often they wake. What is the dependent variable?

All morning students get a new study strategy and all afternoon students get the old strategy. What is the confounding variable?

In a stress study, seniors receive meditation training and freshmen are put on a waitlist. What is the confounding variable?

One memory group studies flashcards in a bright room; another uses notes in a dim room. What factor is confounded with study method?

A school compares active learning taught by Ms. Chen with lecture taught by Mr. Davis. What would most threaten the experiment?

What term names an outside factor that varies with the independent variable and could affect the dependent variable?

A researcher draws names from the entire school roster to invite students into a survey. Is this random selection, random assignment, or matched pairing?

After volunteers arrive, a coin flip sends each person to the sleep-deprivation group or the normal-sleep group. Is this random assignment, random selection, or sampling bias?

A pollster uses a random-number generator to pick phone numbers from all households in a city. What procedure is being used?

A study first recruits volunteers from one psychology class, then uses a computer to put them in treatment or control groups. What part is random assignment?

A researcher wants the sample to represent all students in a district, not just volunteers from one class. What procedure best serves that goal?

What is an operational definition in a psychology study?

A study defines stress as heart rate during a three-minute speech. What part of the study is this definition?

Researchers define happiness as the total score on a 10-item mood survey. What research element is this?

In an attention study, focus is defined as the number of math problems completed in five minutes. What is being provided?

In a double-blind procedure, who is unaware of which participants are in each treatment condition?

Neither the nurses giving pills nor the patients taking them know who receives the real medication or the placebo. What procedure is this?

Participants do not know whether they drank caffeine or a placebo, but the researcher recording results does know. What procedure is this?

In a memory study, one group receives the new training program being tested. What is that group called?

In a study of a study-skills app, one group uses a fake app with no active features for comparison. What is that group?

To test whether a peppermint scent affects recall, all students get the same word list and the same study time. What is a control variable?

A researcher tests whether screen color affects reaction speed and has everyone use the same laptop model. What is a control variable?

A coach tests two practice schedules for free throws while every player uses the same ball and court. What is a control variable?