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 […]
In ANOVA, we always report the F-value, degrees of freedom (df) and p for each effect -possibly just one for one-way ANOVA. P (“Sig.” in SPSS) tells us the likelihood of some effect being zero in our population. However, it doesn’t tell us how strong some effect is if it is not zero; we can’t conclude that p = 0.05 indicates a […]
Summary SPSS MEANS produces tables containing means and/or other statistics for different groups of cases. These groups are defined by one or more categorical variables. If assumptions are met, MEANS can be followed up by an ANOVA. This tutorial walks through its main options, pointing out some tips and tricks. You may follow along by downloading and opening freelancers.sav. […]
Summary SPSS DESCRIPTIVES generates a single table with descriptive statistics for one or more variables. It can also add z-scores to your data. We’ll walk through its major options using freelancers.sav. The screenshot below shows part of its data view. User Missing Values Before running any descriptives, we first need to specify some user missing values for income_2010 through […]
A course was evaluated by 183 students. The data are in course_evaluation.sav, part of which is shown below. The teacher wants to know the average age of his students but we only have their date of birth. 1. Ensure Date of Birth is a Date Variable The first thing we’ll do is check if date of […]
In SPSS, IF is a conditional COMPUTE command. It calculates a (possibly new) variable but only for those cases that satisfy some condition(s). This tutorial walks you through some typical examples of the IF command. Example 1 – Replace Missing Values With the syntax below we’ll first create some test data. Next we’ll set the existing variable score […]
SPSS RECODE replaces data values with different values. It comes in handy for merging categories, dichotomizing continuous variables and some other tasks. This tutorial walks you through its main options, best practices and pitfalls. SPSS Recode Example 1 For quickly getting very proficient with RECODE it’s recommended you follow along with the examples. You’ll soon notice […]
SPSS ALTER TYPE command is mainly used for converting string variables to numeric variables. However, it has other interesting applications as well. This tutorial quickly walks you through those, pointing out some pitfalls, tips and tricks along the way. You can follow along by downloading and opening holidays.sav but you do need SPSS version 16 or higher for using ALTER […]
SPSS System Missing Values SPSS User Missing Values Setting User Missing Values Inspecting Missing Values per Variable SPSS Data Analysis with Missing Values What are “Missing Values” in SPSS? In SPSS, “missing values” may refer to 2 things: System missing values are values that are completely absent from the data. They are shown as periods in data view. […]
Introduction Working with SPSS datetime variables is not hard at all if you understand some basics. This tutorial walks you through just those. Those who’d like to follow along may download and open hospital.sav. SPSS Datetime Variables – What Are They? SPSS datetime variables are variables that hold the numbers of seconds between the year 1582 and […]
A substring is a subset of characters from a string. Extracting substrings in SPSS is done with CHAR.SUBSTR (SPSS versions 16+) or just SUBSTR (SPSS versions 15-). CHAR.SUBSTR takes two or three arguments as shown by the minimal example below. SPSS CHAR.SUBSTR – Minimal Example COMPUTE var_2 = CHAR.SUBSTR(var_1,3,2). The three arguments mean the following: var_1 denotes the variable […]
Understanding SPSS variable types and formats allows you to get things done fast and reliably. Getting a grip on types and formats is not hard if you ignore the very confusing information under variable view. This tutorial takes away the confusion and puts you back in control. We encourage you to follow along with this tutorial by downloading and opening computer_parts. […]
A large bank wants to gain insight into their employees’ job satisfaction. They carried out a survey, the results of which are in bank_clean.sav. The survey included the number of hours people work per week and their gross monthly salaries. Research Question It seems obvious that working hours are related to monthly salaries: employees who work […]
SPSS FREQUENCIES command can be used for much more than frequency tables; it’s also the easiest way to obtain basic charts such as histograms and bar charts. On top of that, it provides us with percentiles and some other statistics. Plenty of reasons for taking a closer look at this ubiquitous SPSS command. We’ll use employees.sav throughout […]
By default, every case in your data counts as a single case. However, you can have each case count as more or less than one case as well. This is called weighting. For instance, the first case in your data may count as 2 cases and the second one as .5 cases. These numbers, the case weights, […]
Summary A previous tutorial covered assembling your own toolbar. This will become even more interesting if you add your own toolbar tools to it. This tutorial quickly walks you through and suggests some best practices. 1. Create a Folder with Syntax and Images Setting Up your SPSS Toolbar Tools Like so may Speed Things Up […]
Summary Toolbars can be very useful in SPSS. They allow users to do a lot of stuff with a single mouse click. However, some users may feel there’s some limitations to their default configuration. An ideal way to get around these is to assemble your own toolbar. Some limitations of standard toolbars Most users will […]
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?
SPSS means “Statistical Package for the Social Sciences” and was first launched in 1968. Since SPSS was acquired by IBM in 2009, it’s officially known as IBM SPSS Statistics but most users still just refer to it as “SPSS”. SPSS – Quick Overview Main Features SPSS is software for editing and analyzing all sorts of data. These data may come […]
SPSS” Syntax Editor window is the second of SPSS’ three main windows. As we’ll see in a minute, this is where we run commands for opening files, editing data, generating results and, finally, saving files. The Syntax Editor is recognized by an orange icon in its left top corner. SPSS Syntax – First Encounter We recommend […]
