Statistical Tests Flashcards
This helps you understand various statistical tests and when to use them.
What is the purpose of a t-test?
To compare the means of two groups to determine if they are significantly different from each other.
T-tests assess whether the means of two groups are statistically different.
Which statistical test is used to compare the means of three or more groups?
ANOVA (Analysis of Variance).
ANOVA determines if there are significant differences among group means.
How does a chi-square test function?
It evaluates whether there is a significant association between categorical variables.
Chi-square tests assess relationships between categorical variables.
List two types of regression analysis.
- Simple linear regression
- Multiple linear regression
Simple linear regression examines the relationship between two variables; multiple linear regression involves more than two.
Fill in the blank:
The Mann-Whitney U Test is a __________ alternative to the independent samples t-test.
non-parametric
It’s used when data doesn’t meet parametric test assumptions.
True or False:
The Wilcoxon Signed-Rank Test compares two independent samples.
FALSE
It compares two related or paired samples.
Define:
Kruskal-Wallis H Test.
A non-parametric test used to determine if there are statistically significant differences between the distributions of three or more independent groups.
It’s an alternative to one-way ANOVA when assumptions aren’t met.
What is the main assumption of parametric tests?
Data follows a normal distribution (normality).
Parametric tests assume normality and other specific conditions.
Which test would you use to assess the relationship between two continuous variables?
Pearson correlation coefficient.
It measures the strength and direction of the linear relationship between two continuous variables.
How does logistic regression differ from linear regression?
Logistic regression is used for predicting binary outcomes, while linear regression predicts continuous outcomes.
Logistic regression models dichotomous variables; linear regression models continuous variables.
List three common non-parametric tests.
- Mann-Whitney U Test
- Kruskal-Wallis H Test
- Wilcoxon Signed-Rank Test
These tests don’t assume normal distribution and are alternatives to parametric tests.
Fill in the blank:
The ________ test is used to determine if there is a significant difference between observed and expected frequencies in categorical data.
chi-square
It’s commonly used in tests of independence.
True or False:
ANOVA can only be used for independent groups.
TRUE
ANOVA is designed for comparing means across independent groups.
What is Type I error in hypothesis testing?
Rejecting a true null hypothesis (false positive).
It’s the incorrect rejection of a true null hypothesis.
What is a Type II error?
Failing to reject a false null hypothesis (false negative).
It’s the failure to identify a true effect.
Which test would you use to compare the means of two related groups?
Paired samples t-test.
It’s used for comparing means from the same group at different times or under two different conditions.
How does the Kruskal-Wallis H Test differ from ANOVA?
Kruskal-Wallis H Test is non-parametric and doesn’t assume normal distribution; ANOVA is parametric and assumes normality.
Kruskal-Wallis is used when ANOVA assumptions aren’t met.
Fill in the blank:
The ____ test measures the strength and direction of the association between two ranked variables.
Spearman’s rank correlation
It’s a non-parametric measure of rank correlation.
True or False:
The Mann-Whitney U Test requires the assumption of normality.
FALSE
It’s a non-parametric test that doesn’t assume normal distribution.
Define
The purpose of a one-sample t-test.
To determine if the mean of a single sample differs significantly from a known or hypothesized population mean.
It compares a sample mean to a known value.
Which statistical test would you use to examine the association between two categorical variables?
Chi-square test of independence.
It assesses whether there’s a significant association between two categorical variables.
What is the difference between multiple linear regression differ and simple linear regression?
Multiple linear regression involves two or more independent variables; simple linear regression involves only one.
Multiple predictors are used in multiple regression.
Fill in the blank:
The ________ test is used to compare the medians of two independent groups.
Mann-Whitney U
It’s a non-parametric alternative to the independent samples t-test.
True or False:
Non-parametric tests are less powerful than parametric tests when assumptions of parametric tests are met.
TRUE
When parametric assumptions are met, parametric tests are generally more powerful.
Define
Null hypothesis
A statement that there is no significant difference.
It’s the hypothesis that there is no effect or no difference, serving as the default or starting assumption
What is the alternative hypothesis?
A statement that contradicts the null hypothesis.
