AP Psychology · Free-response skill

Evidence, and the limits of a source

The move. State a claim, support it with a specific finding from each of two sources, and explain how a limitation in one source weakens a conclusion drawn from it.

How to do it

  1. Read all three summaries first. For each, note the design (experiment, survey or a before-and-after look at one group), who took part, and the main result with its numbers.
  2. Write a claim that takes one clear side and that at least two sources can support. A claim is a sentence someone could disagree with, not a topic.
  3. For each source you use, name it, give one concrete result, and then say why that result backs the claim. Make the link with a named idea: a psychology concept (such as social facilitation) or a design feature (such as random assignment).
  4. For a limitation, name one specific flaw in one source, such as no comparison group, a small or narrow sample, self-report, or a correlational design. Then say what that flaw leaves open: another explanation for the result, or people the result may not apply to.
  5. Tie the limitation back to a conclusion. Saying a sample is small is half the job; saying why that makes a particular conclusion less certain is the other half.

Practice prompt Try it

Source A (fictional). Okafor randomly assigned 80 college students to type a list of familiar words for five minutes, either alone or while two other students sat nearby and watched. Watched students typed an average of 54 words a minute; students working alone typed 47. Source B (fictional). Halvorsen timed 30 experienced competitive swimmers over the same distance on two days. On the first day each swam alone in an empty pool; on the second day each swam with about 100 spectators in the stands. 24 of the 30 swimmers were faster on the second day. Source C (fictional). Brandt surveyed 200 warehouse workers. Workers who said a supervisor often watched them also reported packing more boxes per hour, with a correlation of r = 0.22.

Use the three sources to respond to each part.

  1. Write a claim about whether having other people watch changes how well people do on simple or well-practiced tasks.
  2. Pick one source. Give a specific result from it that supports your claim. Then explain how that result backs the claim, using a psychology concept or a feature of how the study was done.
  3. Pick a different source. Give a specific result from it that supports your claim. Then explain how that result backs the claim, using a psychology concept or a feature of how the study was done.
  4. Pick one source and point out one weakness in how it was done or who took part. Explain how that weakness makes a conclusion from that source less certain.

Write each part, then check yourself against the checklist. Nothing you type here is saved or graded.

Check yourself and see a model answer

Checklist

Our own checklist of what a full answer does, one line per point. Tick each one your response earns.

0 of 7 points

Model answer, annotated

(a) Having other people watch tends to improve how well people do on simple or well-practiced tasks.

  • Point 1 Takes one clear side in a full sentence, and the sources can back it.

(b) In Source A, students typing familiar words while two others watched averaged 54 words a minute, compared with 47 for students typing alone. Because the students were randomly assigned to the two conditions, the groups were alike except for the audience, so the audience is the likely cause of the faster typing. This is social facilitation: the presence of others raises arousal, which improves performance on easy, well-learned tasks.

  • Point 2 Names Source A and gives the exact averages for both conditions.
  • Point 3 Uses a design feature (random assignment) and a named concept (social facilitation) to connect the result to the claim.

(c) In Source B, 24 of the 30 experienced swimmers were faster when about 100 spectators watched than when they swam alone. This backs the claim through social facilitation: swimming a set distance is a well-practiced skill for these athletes, and faster times in front of an audience are what the concept predicts, since an audience raises arousal and arousal helps well-learned tasks.

  • Point 4 Uses a different source from part b and gives the specific count.
  • Point 5 Connects the result to the claim through a named concept, social facilitation, applied to a well-practiced task.

(d) In Source B, every swimmer swam alone on the first day and with spectators on the second day, so the order of the conditions was fixed. The swimmers may simply have been faster on the second day because of practice from the first swim or a change in how rested they were. That leaves another explanation open, so concluding from Source B that the spectators caused the faster times is less certain.

  • Point 6 Names Source B and a concrete flaw: a fixed order of conditions.
  • Point 7 Says what the flaw leaves open (practice or rest on the second day) and ties it to the conclusion that spectators caused the faster times.