RMS final exam study guide

Confounding Variables

Variables that influence both the IV and DV, causing ambiguity about the cause of changes in the DV.

Selection Bias

The non-random assignment of participants to groups that threatens internal validity.

Independent Variable (IV)

The variable that is manipulated in an experiment to observe its effect on the DV.

Dependent Variable (DV)

The variable that is measured in an experiment; its value depends on the IV.

Random Assignment

Ensures every participant has an equal chance of being placed in any group, reducing bias.

Manipulation Checks

Measures used to confirm that the independent variable was effectively manipulated.

Demand Characteristics

Cues that reveal the experiment's purpose, potentially altering participant behavior.

Measures of Central Tendency

Statistics that describe the center of a dataset, including mean, median, and mode.

Z-scores

Standardized scores indicating how far a score is from the mean in standard deviations.

Sampling Distributions

Distributions of a statistic (e.g., mean) across different samples.

Null Hypothesis (H0)

A hypothesis stating that there is no effect or no difference.

Type I Error

Rejecting a true null hypothesis; a false positive.

Power

The probability of correctly rejecting the null hypothesis.

One-Sample t-Test

A test comparing the sample mean to the population mean when the population SD is unknown.

Two-Sample t-Test

A test comparing the means of two groups.

One-Way ANOVA

A test that assesses 3 or more group means simultaneously.

F-Distribution

A positively skewed distribution used in ANOVA.

Two-Way ANOVA

An analysis that examines interactions between two independent variables.

Effect Size

Quantifies the magnitude of the difference between groups, e.g., Cohen's d.

Confidence Interval

A range likely to include the population mean.

Descriptive Statistics

Statistics that summarize or describe the characteristics of a dataset.

Inferential Statistics

Statistics used to make inferences about a population based on a sample.