Psychological Research and Statistics Flashcards

In which research design does the researcher manipulate one variable while holding all others constant to establish causation?

Answer: True experiment

True experiments with random assignment and manipulation of the independent variable are the gold standard for establishing causal relationships.

The mode is the preferred measure of central tendency when data are:

Answer: Nominal (categorical)

The mode is the only measure of central tendency applicable to nominal data because mean and median require at least ordinal measurement.

A researcher uses debriefing after a deception study. What is the PRIMARY ethical purpose?

Answer: To restore participant understanding and well-being after deception

Debriefing serves to inform participants of the true purpose, remove any false impressions, and address any distress caused by deception.

Which nonparametric test is the appropriate alternative to a one-sample t-test when normality cannot be assumed?

Answer: Wilcoxon signed-rank test

The Wilcoxon signed-rank test compares a single sample's median to a hypothesized value without assuming normality.

Demand characteristics in an experiment refer to cues that:

Answer: Lead participants to guess the study's purpose and alter their behavior accordingly

Demand characteristics are cues in the experimental setting that suggest the expected behavior, potentially inflating or distorting results.

When a distribution has a positive skew, the typical order of measures of central tendency is:

Answer: Mode < Median < Mean

In a positively skewed distribution, the tail pulls the mean highest, followed by the median, with the mode at the peak (lowest of the three).

A within-subjects design reduces error variance primarily by:

Answer: Removing individual difference variance from the error term

Because the same participants appear in all conditions, stable individual differences are partitioned out, reducing unexplained (error) variance.