SPSS transformations between DO IF … and END IF are applied only to cases (rows of data) that satisfy one or more conditions. In many cases, IF is a faster way to accomplish the same results. SPSS Do If Example Say we’d like to convert people’s monthly income into income classes. We may want to use different cut […]
DO REPEAT is a command for running other commands repetitively.SPSS DO REPEAT is often used for looping over (possibly new) variables. VECTOR with LOOP is an alternative way for doing so. Introduction Suppose we have a variable containing values 1 through 4 and we’d like to dichotomize it for a regression analysis. (For some more background, see Creating Dummy Variables in SPSS.) […]
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 […]
ANOVA -short for “analysis of variance”- is a statistical technique for testing if 3(+) population means are all equal. ANOVA – Null Hypothesis Test Statistic – F Assumptions for ANOVA Effect Size – (Partial) Eta Squared ANOVA – Post Hoc Tests The basic idea behind ANOVA: are 3(+) population means all equal? The two simplest […]
Null Hypothesis Assumptions Levene’s test in SPSS Output Reporting Levene’s Test – What Is It? If we want to compare 3(+) groups on a metric variable, we usually want to know if they have different mean scores. In most cases, we’ll run an ANOVA in order to find out. However, this requires the homogeneity assumption which states that the population […]
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 sign test for one median is often used instead of a one sample t-test when the latter’s assumptions aren’t met by the data. The most common scenario is analyzing a variable which doesn’t seem normally distributed with few (say n < 30) observations. * This tutorial shows how to run and interpret a sign test in SPSS. We’ll […]
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 […]
Independent Samples T-Test SPSS Independent Samples T-Test Independent Samples T-Test Other SPSS T-Test Tutorials SPSS Paired Samples T-Test SPSS One Sample T-Test T-Test Background Tutorials Z-Scores – What and Why? What is a Dichotomous Variable?
