Understanding Experiment Designs :Designing, Running, and Analyzing Experiments(Interaction Design Specialization) Answers 2026

Question 1

What might account for random error in an experimental measure?

✅ Natural variation among and within subjects
❌ A systematic flaw in the logging software
❌ A pattern of dropped data for every fifth subject
❌ Biased observations
❌ None of the above

Explanation:
Random error comes from unpredictable natural variability, not from consistent or biased problems (those cause systematic error).

Question 2

Which of the following would be an ordinal response? (Select all that apply)

✅ Responses on a Likert-type scale
❌ Height in centimeters
❌ Favorite color
✅ How spicy each subject prefers Thai food using 1–5 stars
❌ Number of heads from coin flips

Explanation:
Ordinal data has a meaningful order but not equal intervals.

Question 3

Factors are independent variables, and levels are their specific values.

✅ True
❌ False

Question 4

A between-subjects factor is defined as:

❌ Each subject experiences more than one level
✅ Each subject experiences only one level
❌ Each subject experiences all levels
❌ Each subject experiences all but one level
❌ None

Question 5

A within-subjects factor is defined as:

❌ Each subject experiences more than one level
❌ Each subject experiences only one level
✅ Each subject experiences all levels
❌ Each subject experiences all but one level
❌ None

Question 6

If a factor has four levels and subjects experience two of the four, it is:

❌ Within-subjects factor
❌ Between-subjects factor
✅ Partial within-subjects factor
❌ Partial between-subjects factor
❌ None

Question 7

Balanced designs mean every subject experiences every level of every factor.

❌ False
✅ True ❌➡️ Incorrect

Correct Answer:
❌ False

Explanation:
Balanced designs mean equal numbers of observations per condition, not that everyone experiences everything.

Question 8

Most common use of an independent-samples t-test:

❌ One set of subjects, same thing
❌ One set of subjects, two things
❌ Two sets of subjects, same thing
✅ Two sets of subjects that do different things
❌ None

Question 9

Most proper way to report a t-test:

✅ t(14) = 2.76, p = .015
❌ t(14) = 2.76, p < .05
❌ t(1,14) = 2.76, p = .015
❌ t(1,14) = 2.76, p < .05
❌ None

Question 10

A t-test is suited to one factor with two levels.

✅ True
❌ False

🧾 SUMMARY TABLE