T-Tests and T-Distribution Overview

Flashcards focused on key terms and concepts related to t-tests and the t-distribution.

t-distribution

A probability distribution that is similar to the z-distribution but flatter and with fatter tails, used particularly when estimating the population standard deviation from a sample.

z-distribution

A normal distribution that is used when the population standard deviation is known, characterized by a mean of 0 and a standard deviation of 1.

T-Test

A statistical test used to determine if the sample mean is significantly different from a population mean or from another sample mean.

critical value (t-crit)

The threshold value that a t-score must exceed to reject the null hypothesis in a t-test.

degrees of freedom (DF)

A parameter used in statistical tests that represents the number of independent values or quantities that can vary in an analysis.

hypothesis testing

A statistical method used to make decisions about the validity of a hypothesis based on sample data.

Cohen’s D

A measure of effect size that indicates the standardized difference between two means.

effect size

A quantitative measure of the magnitude of the difference between two groups or conditions in psychological research.

null hypothesis (H0)

The hypothesis that there is no effect or difference, used as a default position until evidence suggests otherwise.

alternate hypothesis (HA)

The hypothesis that suggests a potential effect or difference that is opposite to the null hypothesis.

alpha level (α)

The probability of rejecting the null hypothesis when it is true, commonly set at 0.05 or 0.01.

sampling distribution

The probability distribution of a statistic obtained through a large number of samples drawn from a specified population.

t-obtained (t-obt)

The calculated t-score from a sample used to compare against the critical t-score to determine if the null hypothesis should be rejected.