T-Tests: Comparing Means Flashcards
What is a t-test?
A statistic that checks if two means are reliably different from each other.
Descriptive Statistics
Describes the data that you have, such as the mean, but can’t be generalized beyond that.
Inferential Statistics
Statistics, like t-tests, or chi-squared tests, that allow us to make inferences about the population beyond our data.
Formula for t-test
t = variance between the groups / variance within the groups
A Big t-value = ?
Different Groups
A small t-value = ?
Similar Groups
What is the p-value?
The probability that the pattern of the data could be produced by chance, that is random data.
Types of t-tests
- Independent Samples
- Paired-Samples
- 1-Sample
Compare the means of two different groups
Independent Samples t-test
Compare the means of one group, twice (before and after).
Paired Samples t-test
Tests the mean of one group against some other value.
1-Sample t-test
Used to compare counts/percentages between two groups
Chi-Square Test
When do you reject the null hypothesis in a Chi-Square test?
If p
Tests the means of an effect, or treatment on each unit in a set (sample).
Paired t-test
What is the null hypothesis in a paired t-test?
There is no effect
