Practice Test GeeksAP Practice Test
← All AP Flashcard Decks

Experimental Design Flashcards

7 cards from real AP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Experimental Design flashcards as text

  1. A factory tests three machine settings (A, B, C) on product quality. They run all three settings each day for 10 days, randomizing the order each day. The days serve as:

    Answer: Blocks

    The days act as blocks because each day's conditions (temperature, humidity, worker fatigue) are controlled by including all treatments within each day.

  2. The scope of inference from an experiment is most limited when:

    Answer: Subjects volunteer for the study rather than being randomly selected

    Voluntary participation (lack of random sampling) limits generalizability — results may only apply to people willing to volunteer.

  3. An AP Statistics student designs an experiment to test whether background music affects quiz scores. She has 30 students take two quizzes — one with music and one without — on different days, with order randomized. This is a:

    Answer: Matched pairs design

    Each student serves as their own matched pair, experiencing both conditions, which controls for individual differences in ability.

  4. Which of the following would NOT improve the internal validity of an experiment?

    Answer: Including a larger and more diverse volunteer pool

    Using a larger or more diverse volunteer pool improves external validity (generalizability), not internal validity (causal conclusions within the study).

  5. A researcher studying sleep deprivation randomly assigns college students to 4, 6, or 8 hours of sleep, then measures reaction time. The experimental units are:

    Answer: The college students

    Experimental units are the individuals (students) to whom treatments (sleep durations) are randomly assigned.

  6. In a drug trial, a researcher wants to ensure that the proportion of males and females is equal across treatment groups. The best design strategy is to:

    Answer: Block by gender, then randomly assign within each gender block

    Blocking by gender before random assignment guarantees equal gender representation across treatment groups.

  7. A study finds that ice cream sales and drowning rates are positively correlated. The most likely explanation is that:

    Answer: A lurking variable (hot weather) causes both to increase

    Hot weather increases both ice cream consumption and swimming, creating a spurious correlation between ice cream sales and drowning rates.