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What is the difference between t-test and paired t-test?
Two-sample t-test is used when the data of two samples are statistically independent, while the paired t-test is used when data is in the form of matched pairs.
What are the assumptions for a paired t-test?
Paired t-test assumptions
- Subjects must be independent. Measurements for one subject do not affect measurements for any other subject.
- Each of the paired measurements must be obtained from the same subject.
- The measured differences are normally distributed.
Are paired and dependent t tests the same?
The dependent t-test (also called the paired t-test or paired-samples t-test) compares the means of two related groups to determine whether there is a statistically significant difference between these means.
Why would you use a paired t-test?
A paired t-test is used when we are interested in the difference between two variables for the same subject. Often the two variables are separated by time. Since we are ultimately concerned with the difference between two measures in one sample, the paired t-test reduces to the one sample t-test.
How do you determine if data is paired?
Two data sets are “paired” when the following one-to-one relationship exists between values in the two data sets.
- Each data set has the same number of data points.
- Each data point in one data set is related to one, and only one, data point in the other data set.
What is another name for paired t procedures?
The paired sample t-test, sometimes called the dependent sample t-test, is a statistical procedure used to determine whether the mean difference between two sets of observations is zero.
What does a paired t-test show?
The Paired Samples t Test compares the means of two measurements taken from the same individual, object, or related units. These “paired” measurements can represent things like: A measurement taken at two different times (e.g., pre-test and post-test score with an intervention administered between the two time points)
When to use a paired t test?
The paired t-test is used when the variable is numerical in nature (for example, the height of a person or the weight of a person) and the individuals in the sample are either paired up in some way (such as a husband and wife) or the same people are used twice (for example, preprocedure and postprocedure).
When to use unpaired t test?
An independent t-test, also known as an unpaired t-test, is a parametric statistical test used to determine if there are any differences between two continuous variables on the same scale from two unrelated groups. For example, comparing height differences between a sample of male and females.
What is an example of a paired t test?
The paired sample t-test is also called dependent sample t-test. It’s an univariate test that tests for a significant difference between 2 related variables. An example of this is if you where to collect the blood pressure for an individual before and after some treatment, condition, or time point.
What are paired t test assumptions?
The paired sample t-test has four main assumptions: • The dependent variable must be continuous (interval/ratio). • The observations are independent of one another. • The dependent variable should be approximately normally distributed. • The dependent variable should not contain any outliers.