Untitled Flashcards Set

What is the null hypothesis (H₀)?

The IV will not have an effect on the DV.

What is the alternative hypothesis (H₁)?

The IV will have an effect on the DV.

What is a p-value?

The probability that the observed difference between means is due to error variance.

When is a result considered statistically significant?

When the p-value is less than the alpha level (commonly 0.05).

Why do journals encourage reporting effect sizes?

To quantify how much the IV impacts the DV.

What is the file-drawer problem?

The tendency for nonsignificant findings to go unpublished, leading to biased understanding of research.

What is Type I error?

Rejecting the null hypothesis when it is true (false positive).

What is Type II error?

Failing to reject the null hypothesis when it is false (false negative).

What is statistical power?

The probability of correctly rejecting a false null hypothesis.

What is p-hacking?

Over-analyzing data to make nonsignificant results significant.

What is Cohen's d?

A measure of effect size indicating the difference between two group means relative to standard deviation.

How does a quasi-experiment differ from a true experiment?

Quasi-experiments lack random assignment and have less control over IV manipulation.

What is regression to the mean?

The tendency for extreme scores to move closer to the mean with repeated testing.

What is a nonequivalent control group design?

A design that uses a similar but non-randomly assigned control group.

What is a one-group pretest-posttest design?

A study measuring participants before and after an intervention, but without a control group.

What is an ABA design?

A single-case experimental design with baseline (A), intervention (B), and return to baseline (A).

What is an ABAB design?

A variation of the ABA design, adding a second intervention to confirm effects.

When is a single-case design unethical?

When withdrawing a beneficial intervention could harm participants (e.g., removing effective medication).

What is a local history effect?

An external event that affects only one group during a study.

What is the difference between nomothetic and idiographic approaches?

Nomothetic focuses on group means and generalizations, while idiographic analyzes individual behavior in detail.

What are two limitations of case studies?

Observer bias and failure to control extraneous variables.

What does NHST stand for?

Null Hypothesis Significance Testing.

What is the purpose of NHST?

To determine if observed differences exceed what is expected by error variance.

What is the alpha level?

The threshold probability (commonly 0.05) for rejecting the null hypothesis.

What is an ANOVA used for?

To analyze differences between group means when the IV has more than two levels.