What are the assumptions of independent t test?
The common assumptions made when doing a t-test include those regarding the scale of measurement, random sampling, normality of data distribution, adequacy of sample size and equality of variance in standard deviation.
How do you interpret a paired t test?
If the p-value is less than or equal to the significance level, the decision is to reject the null hypothesis. You can conclude that the difference between the population means is statistically significant. Use your specialized knowledge to determine whether the difference is practically significant.
What does a paired t test show?
The Paired Samples t Test compares two means that are from the same individual, object, or related units. The two means can represent things like: A measurement taken at two different times (e.g., pre-test and post-test with an intervention administered between the two time points)
How do I know if my 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 the difference between dependent and independent t test?
Dependent samples occur when you have two samples that do affect one another. Independent samples occur when you have two samples that do not affect one another. The likelihood is the test statistic (t) associated with two dependent samples.
What is the difference between independent and paired t test?
An Independent Samples t-test compares the means for two groups. A Paired sample t-test compares means from the same group at different times (say, one year apart). A One sample t-test tests the mean of a single group against a known mean.
What is an independent t test used for?
The Independent Samples t Test compares the means of two independent groups in order to determine whether there is statistical evidence that the associated population means are significantly different. The Independent Samples t Test is a parametric test.
How do you know if two samples are independent?
Therefore, it’s important to know whether your samples are dependent or independent:If the values in one sample affect the values in the other sample, then the samples are dependent.If the values in one sample reveal no information about those of the other sample, then the samples are independent.
What is the difference between a paired t test and a 2 sample 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. To use the two-sample t-test, we need to assume that the data from both samples are normally distributed and they have the same variances.
What is an example of 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. For example, in the Dixon and Massey data set we have cholesterol levels in 1952 and cholesterol levels in 1962 for each subject.
What is a 2 sample t test?
The two-sample t-test is a method used to test whether the unknown population means of two groups are equal or not.