T-Test & Confidence Interval Review

Flashcards covering key vocabulary and concepts related to t-Tests and Confidence Intervals in statistics.

t-Test

A statistical test used to compare the means of two groups.

Confidence Interval

A range of values derived from a data set that is likely to contain the true value of an unknown population parameter.

Null Hypothesis (H0)

A statement that there is no effect or no difference; it serves as the default position that indicates no change.

Alternative Hypothesis (H1)

The hypothesis that there is a significant effect or difference; it is what researchers aim to support.

Dependent Samples

Samples where the measurements are paired or related in some way.

Independent Samples

Samples that are not related to each other.

Sampling Distribution

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

Mean Differences

The average of the differences between paired observations in dependent samples.

Standard Deviation (SD)

A measure of the amount of variation or dispersion in a set of values.

Test Statistic

A standardized value that is calculated from sample data during a hypothesis test.

t-Critical Value

The point(s) beyond which the null hypothesis will be rejected in a t-test.

Alpha Level (α)

The probability of rejecting the null hypothesis when it is actually true, typically set at 0.05.

Point Estimate

A single value estimate of a population parameter.

Margin of Error

The amount of error that is allowed in the results of a survey or statistical analysis.

Two-Tailed Test

A hypothesis test that evaluates for the possibility of the relationship in both directions.

One-Tailed Test

A hypothesis test that evaluates for the possibility of the relationship in one specific direction.

Degrees of Freedom (df)

The number of independent values in a calculation, often expressed as n-1 for sample statistics.

p-Value

The probability of observing a test statistic as extreme as the one observed, under the assumption that the null hypothesis is true.

Rejecting the Null Hypothesis

The conclusion made when the evidence suggests that the null hypothesis is not true.

Failing to Reject the Null Hypothesis

The conclusion made when there is not enough evidence to support the alternative hypothesis.

Confidence Level

The percentage that indicates how confident we are that the confidence interval contains the true population parameter.

Two-Sample t-Test

A test used to compare the means of two independent samples.

Related Samples t-Test

A test used to compare the means of two related groups.

Standard Error of the Mean (SEM)

An estimate of how far the sample mean is likely to be from the population mean.

Effect Size

A quantitative measure of the magnitude of a phenomenon.

Bootstrapping

A statistical method that resamples a single dataset to create a distribution.

Confidence Interval for Means

A range of values that is likely to include the population mean.

Hypothesis Testing

A method of statistical inference used to decide if the data at hand sufficiently support a particular hypothesis.

Independent Groups

Two or more groups that are not influenced by the same subject or the same condition.

Dependent Groups

Groups in which the participants or observations are related.

Interpretation of Results

The process of explaining what the statistical output means in the context of the study.

Mean (μ)

The average value of a set of numbers.

Sampling Error

The error caused by observing a sample instead of the whole population.

Statistical Significance

A determination that results are not likely to occur by chance alone.

Hypothesis

A proposed explanation for a phenomenon, serving as the basis for further investigation.

Cohen's d

A measure of effect size used to indicate the standardized difference between two means.

Statistical Power

The probability that a test will correctly reject a false null hypothesis.

Variance (σ²)

A statistical measurement of the spread between numbers in a dataset.

Sample Size (n)

The number of observations in a sample.

Regression Analysis

A statistical process for estimating the relationships among variables.