Independent Samples T-Test – What Is It? Null Hypothesis Test Statistic Assumptions Statistical Significance Effect Size Independent Samples T-Test – What Is It? An independent samples t-test evaluates if 2 populations have equal means on some variable.If the population means are really equal, then the sample means will probably differ a little bit but not […]
SPSS paired samples t-test is a procedure for testing whether the means of two metric variables are equal in some population. Both variables have been measured on the same cases. Although “paired samples” suggests that multiple samples are involved, there’s really only one sample and two variables. The screenshot below illustrates the basic idea. SPSS […]
SPSS one-sample t-test tests if the mean of a single metric variable is equal to some hypothesized population value. The figure illustrates the basic idea. SPSS One Sample T-Test – Example A scientist from Greenpeace believes that herrings in the North Sea don’t grow as large as they used to. It’s well known that – on average – […]
A dichotomous variable is a variable that contains precisely two distinct values.Let’s first take a look at some examples for illustrating this point. Next, we’ll point out why distinguishing dichotomous from other variables makes it easier to analyze your data and choose the appropriate statistical test. Examples Regarding the data in the screenshot: completed is not a dichotomous variable. It […]
Z-scores are linearly transformed data values having a mean of zero and a standard deviation of 1.Z-scores are also known as standardized scores; they are scores (or data values) that have been given a common standard. This standard is a mean of zero and a standard deviation of 1. Contrary to what many people believe, z-scores are not necessarily […]
Null Hypothesis Assumptions Independent Samples T Test in SPSS Output Reporting Null Hypothesis The null hypothesis for an independent samples t test is that two populations have equal means on some metric variable. For example, do men spend the same amount of money on clothing as women? We can’t reasonably ask the entire population of men and women how much they […]
