Final Notes

P-Value

The probability of obtaining the observed results, or more extreme results, if the null hypothesis is true.

Central Limit Theorem

States that the sampling distribution of the sample mean will approximate a normal distribution if the sample size is sufficiently large, regardless of the population's shape.

Type I Error

Rejecting the null hypothesis when it is actually true, denoted by α.

Type II Error

Failing to reject the null hypothesis when it is actually false, denoted by β.

Mediation

A process in which an independent variable affects a dependent variable through one or more mediator variables.

Moderation

Occurs when the relationship between two variables depends on a third variable, called the moderator.

Principal Component Analysis (PCA)

A data reduction technique used to reduce many variables into a smaller set of components that explain most of the variation in the data.

Descriptive Statistics

Statistics that summarize and analyze data using measures of central tendency and variability.

Independent Variable

The variable that influences or predicts the dependent variable; it does not depend on other variables.

Dependent Variable

The outcome that depends on the independent variable.

Validity

Whether the measurement actually measures what it is supposed to measure.

Reliability

Whether the measurement is free from errors or bias.

Confidence Interval

A range of values that is likely to contain the true population parameter with a specified level of confidence.

Null Hypothesis (H0)

The assumption that there is no effect or no relationship between variables.

Alternative Hypothesis (H1)

The assumption that there is an effect or a relationship between variables.

Standard Normal Distribution

A special type of normal distribution with a mean of 0 and a standard deviation of 1.

Z-score

The number of standard deviations a data point is from the mean of the dataset.

Factor Analysis

A statistical method that explains variability among observed, correlated variables in terms of a smaller number of unobserved variables called factors.

Degrees of Freedom

The number of values in a calculation that can vary after certain constraints are applied.

ANOVA

A statistical method used to determine whether there are significant differences between the means of three or more groups.

Odds Ratio

A measure of the change in the odds of the dependent variable being 1 when the independent variable increases by one unit.