T-test

Introduction

Execute t-test, which checks differences of means of variables.

How to Access?

You can access from 'Add' (Plus) button.

How to Use?

Column Selection

• Value Column - Numeric column whose means should be calculated.

• Group Column (Optional) - Label column of 2 groups. Without this argument, one sample test, which compares mean with "True Effect Size" value, will be executed.

Parameters

• Type of Alternative Hypothesis (Optional) - The default is "two.sided". What kind of alternative hypothesis to be used. This can be

  • "two.sided"

  • "less"

  • "greater"

• True Effect Size (Optional) - The default is 0. If it's one sample test, true value of the mean. If it's two sample test, the difference in means.

• Paired (Optional) - The default is FALSE. If it should be paired t-test, which is often used to test before values and after values are different.

• Equal Variance (Optional) - The default is FALSE. If the variances of the two groups can be considered as equal.

• Confidence Level (Optional) - The default is 0.95. The level of confidence interval.

• Subset (Optional) - A vector to specify a subset of observations to be used.

• NA Action (Optional) - The default is "na.fail". This changes the behaviour of NA data. Can be one of the following.

  • "na.omit"

  • "na.fail"

  • "na.exclude"

  • "na.pass"

  • NULL

Take a look at the reference document for the 't.test' function from base R for more details on the parameters.