SPSS is a widely used program for statistical analysis in social science. It is also used by market researchers, health researchers, survey companies, government, education researchers, marketing organizations, data miners, and others. The original SPSS manual (Nie, Bent & Hull, 1970) has been described as one of “sociology’s most influential books” for allowing ordinary researchers to do their own statistical analysis. In addition to statistical analysis, data management (case selection, file reshaping, creating derived data) and data documentation (a metadata dictionary is stored in the datafile) are features of the base software.
Managing variable and value labels without syntax is way more work than necessary. This tutorial explains how to do this more efficiently. Changing Variable Labels in SPSS As with other parts of the dictionary, there’s no “Paste” option for modifying variable labels. Be aware that manual modifications – apart from being time consuming – are not […]
Summary SPSS RANK can be used to create a variable holding the rank numbers of the values of some other variable. RANK is also used for discretizing continuous variables into ntile groups. This tutorial walks you through the main options along with some real world examples. Result of first RANK syntax example 1. SPSS Rank Basic Example Running the syntax below first creates […]
We think SPSS with Python is great! However, you need to have the SPSS Python Essentials properly installed in order to use it. This tutorial gives a quick overview of installing and then testing them for different SPSS versions. SPSS Python Essentials The basic components you need for running Python in SPSS are SPSS; Python; the SPSS Python plugin. […]
MATCH FILES is an SPSS command mostly used for merging data holding similar cases but different variables. For different cases but similar variables, use ADD FILES. MATCH FILES is also the way to go for a table lookup similar to VLOOKUP in Excel. Merging two datasets by id, which is a unique case identifier. SPSS Match Files – Basic Use The […]
While working in SPSS, it’s pretty common to reorder your variables. This tutorial shows how to do so the right way. We encourage you try the examples for yourself by downloading and opening hotel_evaluation.sav, a screenshot of which is shown below. SPSS Reorder Variables Example 1 Right, the most common way for reordering variables in SPSS […]
Introduction An escape sequence is a combination of characters that has a special meaning. Escape Sequences in General Some characters imply a special function rather than their “normal” meaning. For example, ‘ often implies the start or the end of a string. But what if you actually mean ‘ rather than a string? In that case you can escape its default meaning by prefixing […]
A car brand had 18 respondents rate 3 different car ads on attractiveness. The resulting data -part of which are shown above- are in adratings.sav. Some background variables were measured as well, including the respondent’s gender. The question we’ll try to answer is:are the 3 ads rated equally attractive and does gender play any role here?Since […]
What is Repeated Measures ANOVA? Repeated Measures ANOVA Assumptions Quick Data Check Running Repeated Measures ANOVA in SPSS Interpreting the Output Reporting Repeated Measures ANOVA 1. What is Repeated Measures ANOVA? SPSS repeated measures ANOVA tests if the means of 3 or more metric variables are all equal in some population. If this is true and we inspect a sample from our […]
Null Hypothesis Assumptions Example Repeated Measures ANOVA – Basic Formulas Post Hoc Tests Null Hypothesis The null hypothesis for a repeated measures ANOVA is that3(+) metric variables have identical means in some population. The variables are measured on the same subjects so we’re looking for within-subjects effects(differences among means). This basic idea is also referred to as dependent, […]
For testing if 3 or more variables have identical population means, our first option is a repeated measures ANOVA. This requires our data to meet some assumptions -like normally distributed variables. If such assumptions aren’t met, then our second option is the Friedman test: a nonparametric alternative for a repeated-measures ANOVA. Strictly, the Friedman test can […]
SPSS Cochran Q test is a procedure for testing if the proportions of 3 or more dichotomous variables are equal in some population. These outcome variables have been measured on the same people or other statistical units. SPSS Cochran Q Test Example The principal of some university wants to know whether three examns are equally difficult. Fifteen […]
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 COMPUTE command sets the data values for (possibly new) numeric variables and string variables. These values are usually a function (such as MEAN, SUM or something more advanced) of other variables. This tutorial walks you through doing just that. We’ll use hospital.sav,a screenshot of which is shown below. Before proceeding, we’ll first set 6 as a user missing value for the last 5 […]
The sign test for two medians evaluates if 2 variables measured on 1 group of cases are likely to have equal population medians.* It can be used on either metric variables or ordinal variables. For comparing means rather than medians, the paired samples t-test and Wilcoxon signed-ranks test are better options. Adratings Data We’ll use adratings.sav throughout this tutorial. It holds data on 18 respondents […]
For comparing two metric variables measured on one group of cases, our first choice is the paired-samples t-test. This requires the difference scores to be normally distributed in our population. If this assumption isn’t met, we can use Wilcoxon S-R test instead. It can also be used on ordinal variables -although ties may be a real issue for Likert items. […]
SPSS McNemar test is a procedure for testing if the proportions of two dichotomous variables are equal in some population. The two variables have been measured on the same cases. SPSS McNemar Test Example A marketeer wants to know whether two products are equally appealing. He asks 20 participants to try out both products and […]
A hospital wants to know how a homeopathic medicine for depression performs in comparison to alternatives. They administered 4 treatments to 100 patients for 2 weeks and then measured their depression levels. The data, part of which are shown above, are in depression.sav. Data Inspection – Split Histogram Before running any statistical tests, let’s first just […]
SPSS One-Way ANOVA tests if the means on a metric variable for three or more populations are all equal. * The populations are identified in the sample by a categorical variable. For a very simple explanation of the basic idea, see ANOVA – What Is It?. SPSS One-Way ANOVA Example A farmer wants to know if the weight of parsley plants is […]
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 […]
Research Question How to lose weight effectively? Do diets really work and what about exercise? In order to find out, 180 participants were assigned to one of 3 diets and one of 3 exercise levels. After two months, participants were asked how many kilos they had lost. These data -partly shown above- are in weightloss.sav. We’re […]
