2021, Set 2, Question 2 · Research Design · 7 points

2021 AP Psychology FRQ 2 (Set 2) answers

Mental imagery and word-pair recall experiment

For an experiment comparing recall of word pairs with and without imagery instructions, name the independent variable and control group, defend the design, interpret two standard deviations, spot the ethics problem, and link the primacy effect and levels of processing.

Skip to the worked answer and scoring (try the question first if you can)

This exam had two free-response questions to answer in 50 minutes, a Concept Application question and a Research Design question, each scored out of 7 points. The current exam has 2 free-response questions in 70 minutes. The skills these questions practice still count.

Lessons this question draws on

1 Read the question

The question is College Board's, from the 2021, Set 2 exam. It starts on page 3 of the PDF. College Board no longer posts this exam, so it opens from the copy of College Board's PDF that the Internet Archive saved on March 15, 2026.

Open Question 2 (PDF, page 3)

2 Write your answer

Answer each part the way you would on the exam, in full sentences, with your work shown. Your writing saves as you type.

Your answer

3 Score it

Score your answer against College Board's scoring guidelines, one point at a time. Give yourself a point only when your answer says what the guideline asks for.

Scoring guidelines (PDF, page 7) What the exam readers saw (Chief Reader report)

4 Worked answer and scoring

Here is how a response that earns full credit could read, part by part, and what College Board's scoring guidelines look for, put in our own words. Open a part once you have written your own answer to it. The scoring guidelines PDF above is the official word on every point.

Dr. Jones randomly assigned students and gave only one group an instruction, so this is a true experiment with an experimental group (A) and a control group (B). The table gives each group's mean and standard deviation. Seven bullets, one point each.

The answer 7 points

Model answer

Independent variable: whether students were told to form a mental image for each word pair.

Control group: Group B, the students given no imagery instruction.

Why the design fits: this is an experiment. Dr. Jones manipulated the imagery instruction and randomly assigned students to the two conditions, so a difference in recall can be credited to the imagery itself. Only an experiment can support that cause and effect conclusion, which is exactly what a study of the effect of imagery on memory needs.

Standard deviations: Group B's standard deviation (6) is larger than Group A's (4), so the recall scores in Group B were more spread out and the scores in Group A sat closer together around their mean.

Ethical flaw: the students were made to take part as a course requirement. Participation in research must be voluntary, with the freedom to decline.

Primacy effect: students in both groups would tend to recall more of the pairs near the start of the list of thirty than pairs from the middle.

Levels of processing: forming a mental image of each pair is deeper processing than just repeating the words, so Group A encoded the pairs more deeply and recalled more (25 against 10), while Group B's shallower processing produced weaker recall.

What earns each point

The independent variable is mental imagery, or the instruction to use it. The independent variable is what the researcher changes between groups. The word pairs were the same for everyone, so they are materials, not the variable.
The control group is Group B, the one not told to use imagery. The control group does not get the treatment and serves as the comparison.
The design is an experiment, and it fits because the aim is to show cause and effect. Both halves are needed: naming the method and saying why it suits the question. Manipulating one variable with random assignment is what lets the study say imagery caused better recall.
Group B's scores varied more than Group A's (or Group A's varied less). Standard deviation measures spread around the mean, so the larger value, 6, belongs to the more scattered group. Both groups had forty students, so group size cannot explain the difference.
Students were required to participate, so participation was not voluntary. Requiring the task as coursework removes the right to decline. She did debrief them, so debriefing is not the flaw, and harm is not stated anywhere in the scenario.
Students would recall more of the words from the beginning of the list than from other parts of it. The primacy effect is better memory for early items in a list. Describing the whole serial position curve without picking out the beginning, or confusing it with priming, misses it.
Group A, using imagery, processed the words deeply and recalled more, or Group B processed shallowly and recalled less. Levels of processing says deeper encoding lasts longer. The answer has to use deep or shallow processing, not a general claim that imagery helps.

Common mistakes

From what the exam readers reported seeing in 2021 students' answers, in our words:

Naming the stimulus materials, the word pairs, as the independent variable instead of the imagery instruction. This was often the error.
Saying the design is an experiment without adding that experiments can show cause and effect, which responses frequently left out.
Describing the serial position effect in general instead of the primacy effect, or mistaking primacy for priming. Responses often did one or the other.
Writing about higher levels of learning rather than depth of processing or depth of encoding, which happened often.

Question, scoring guidelines and Chief Reader report: College Board, from the Internet Archive. The title, summary and worked answer are ours.