Mixed Models: Can you specify a predictor as both fixed and random?

February 16th, 2016 by

One of the most confusing things about mixed models arises from the way it’s coded in most statistical software.  Of the ones I’ve used, only HLM sets it up differently and so this doesn’t apply.

But for the rest of them—SPSS, SAS, R’s lme and lmer, and Stata, the basic syntax requires the same pieces of information.

1.       The dependent variable

2.       The predictor variables for which to calculate fixed effects and whether those (more…)

How to Get SPSS GENLINMIXED Output Without the Model Viewer

September 26th, 2014 by

I love working with my clients.

I love working with my clients for many reasons, but one of them is I learn so much from them.

Just this week, one of my clients showed me how to get SPSS GENLINMIXED results without the Model Viewer.

She’s my new hero.

If you’ve ever used GENLINMIXED, the procedure for Generalized Linear Mixed Models, you know that the results automatically appear in this new Model Viewer.  (more…)

SPSS Procedures for Logistic Regression

May 15th, 2014 by

Need to run a logistic regression in SPSS? Turns out, SPSS has a number of procedures for running different types of logistic regression.

Some types of logistic regression can be run in more than one procedure.  For some unknown reason, some procedures produce output others don’t.  So it’s helpful to be able to use more than one.

Logistic Regression

SPSS Binary Logistic Regression MenuLogistic Regression can be used only for binary dependent (more…)

Ten Ways Learning a Statistical Software Package is Like Learning a New Language

January 31st, 2014 by

Someone recently asked me if they need to learn R.  In responding, it struck me that this is another way that learning a stat package is like learning a new language.

The metaphor is extremely helpful for deciding when and how to learn a new stat package, and to keep you going when the going gets rough. (more…)

Using Python with SPSS

December 9th, 2013 by

by Lucy Fike

We know that using SPSS syntax is an easy way to organize analyses so that you can rerun them in the future without having to go through the menu commands.

Using Python with SPSS makes it much easier to do complicated programming, or even basic programming, that would be difficult to do using SPSS syntax alone. You can use scripting programming in Python to create programs that execute automatically. (more…)

Non-parametric ANOVA in SPSS

November 1st, 2013 by

I sometimes get asked questions that many people need the answer to.  Here’s one about non-parametric ANOVA in SPSS.


Is there a non-parametric 3 way ANOVA out there and does SPSS have a way of doing a non-parametric anova sort of thing with one main independent variable and 2 highly influential cofactors?

Quick Answer:


Detailed Answer:

There is a non-parametric one-way ANOVA: Kruskal-Wallis, and it’s available in SPSS under non-parametric tests.  There is even a non-paramteric two-way ANOVA, but it doesn’t include interactions (and for the life of me, I can’t remember its name, but I remember learning it in grad school).

But there is no non-parametric factorial ANOVA, and it’s because of the nature of interactions and most non-parametrics.

What it basically comes down to is that most non-parametric tests are rank-based. In other words, (more…)