2026 | University of Amsterdam Psychology
Entrance Practice Test | Complete Exam
Questions with VERIFIED Answers & WELL
DETAILED Explanations | Latest 2025/2026
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Question 1 In a randomized controlled trial, the primary purpose of random assignment is to:
A. Ensure equal sample sizes across groups B. Control for confounding variables C.
Increase the statistical power of the study D. Reduce measurement error E. Guarantee external
validity
RATIONALE: Random assignment distributes both known and unknown confounding
variables evenly across groups, ensuring that differences in outcomes can be attributed to the
independent variable rather than pre-existing group differences.
Question 2 Which type of validity refers to whether a test measures what it claims to measure?
A. External validity B. Ecological validity C. Construct validity D. Concurrent validity E.
Face validity
RATIONALE: Construct validity evaluates whether a psychological test genuinely
measures the theoretical construct it is designed to assess, ensuring the test is theoretically sound
and not merely measuring something superficially similar.
Question 3 A researcher finds a correlation of r = −0.85 between stress and academic
performance. This indicates:
A. Stress causes poor academic performance B. A strong positive relationship C. A weak
negative relationship D. A strong negative relationship E. No meaningful relationship
RATIONALE: A correlation of −0.85 is close to −1.0, indicating a strong negative (inverse)
relationship: as stress increases, academic performance decreases. However, correlation does not
imply causation.
,Question 4 In a normal distribution, approximately what percentage of scores fall within two
standard deviations of the mean?
A. 68% B. 90% C. 95% D. 99% E. 75%
RATIONALE: The empirical rule states that in a normal distribution, ~68% of scores fall
within ±1 SD, ~95% within ±2 SD, and ~99.7% within ±3 SD of the mean.
Question 5 The p-value in a hypothesis test represents:
A. The probability that the null hypothesis is true B. The probability of obtaining results at
least as extreme as observed, assuming the null hypothesis is true C. The size of the
effect found in the study D. The probability that the alternative hypothesis is true E. The
confidence level of the study
RATIONALE: The p-value is the probability of obtaining data as extreme as, or more
extreme than, observed results if the null hypothesis were true. It does not indicate the
probability that the null hypothesis is true.
Question 6 Which research design allows researchers to make causal inferences?
A. Case study B. Correlational study C. Naturalistic observation D. Experiment E. Survey
RATIONALE: Only a true experiment, where the researcher manipulates an independent
variable and randomly assigns participants to conditions, allows causal inferences to be drawn.
Other designs can identify associations but not causation.
Question 7 A Type I error in hypothesis testing occurs when:
A. The null hypothesis is false but not rejected B. The null hypothesis is true but is rejected
C. The sample size is too small D. The effect size is too large E. The measurement is
unreliable
RATIONALE: A Type I error (false positive) occurs when a researcher incorrectly rejects a
true null hypothesis, concluding there is an effect when none exists. The probability of a Type I
error equals the alpha (significance) level.
,Question 8 Which statistical test is most appropriate for comparing means of three or more
independent groups?
A. Independent samples t-test B. Paired samples t-test C. One-way ANOVA D. Chi-square
test E. Pearson correlation
RATIONALE: One-way ANOVA (Analysis of Variance) is designed to compare means
across three or more independent groups. Using multiple t-tests inflates the Type I error rate;
ANOVA controls for this.
Question 9 Reliability in psychological measurement refers to:
A. Whether a test measures what it claims to measure B. The consistency of a measurement
C. The degree to which results can be generalized D. The absence of systematic bias E. The
accuracy of causal inferences
RATIONALE: Reliability refers to the consistency and stability of a measurement — a
reliable test produces the same results under the same conditions. Validity (measuring the right
construct) is distinct from reliability.
Question 10 In a double-blind study:
A. Only the participants are unaware of group assignment B. Only the researchers are unaware of
group assignment C. Both participants and researchers are unaware of group assignment
D. The study uses two separate control groups E. The data is analyzed twice for accuracy
RATIONALE: In a double-blind design, neither participants nor the researchers who
interact with them know who is in the experimental or control condition, eliminating both
demand characteristics and experimenter bias.
Question 11 Which sampling method gives every member of the population an equal chance of
being selected?
A. Convenience sampling B. Purposive sampling C. Snowball sampling D. Simple random
sampling E. Stratified sampling
RATIONALE: Simple random sampling ensures every individual in the population has an
equal and independent chance of being selected, making it the gold standard for achieving a
representative sample.
, Question 12 An operational definition is:
A. A theoretical explanation of a construct B. A precise, measurable description of how a
variable will be measured C. The hypothesis being tested D. A description of the study
population E. The ethical guidelines for a study
RATIONALE: An operational definition specifies exactly how a variable will be measured
or manipulated, making abstract concepts concrete and allowing for replication (e.g.,
operationalizing 'anxiety' as score on the GAD-7 scale).
Question 13 Effect size is important in research because it:
A. Determines statistical significance B. Indicates the practical significance of findings C.
Controls for Type II errors D. Establishes causation E. Measures reliability
RATIONALE: Effect size quantifies the magnitude of a relationship or difference,
indicating practical significance. A statistically significant result with a tiny effect size may be
meaningless in practice; effect size communicates real-world importance.
Question 14 The Hawthorne effect refers to:
A. Participants behaving differently because they know they are being observed B.
Researchers unconsciously influencing results C. The tendency for results to regress toward the
mean D. Publication bias in research E. Observer bias in naturalistic studies
RATIONALE: The Hawthorne effect describes the phenomenon where individuals modify
their behavior because they are aware of being observed, potentially confounding study results. It
was first observed in studies at the Hawthorne Works factory.
Question 15 A longitudinal study differs from a cross-sectional study in that:
A. It uses different participants from different age groups B. It follows the same participants
over time C. It involves more participants D. It uses experimental rather than correlational
methods E. It is conducted in a laboratory setting