Configural Frequency Analysis

Configural Frequency Analysis with Mark Stemmler

May 3, 2011 Host Michael Cleveland interviews Mark Stemmler, professor of psychological methodology and quality assurance and dean of the Faculty of Psychology and Sports Science, Bielefeld University, Germany. Dr. Stemmler was a visiting scholar at The Methodology Center in fall of 2010. Micheal talks with Mark about configural frequency analysis, a tool for the analysis of multivariate categorical data. They also discuss Dr. Stemmler’s experiences visiting The Methodology Center and teaching at Penn State.

Podcast Timeline:

00:00 - Introduction 00:48 - Dr. Stemmler's background and relationship with the Methodology Center 03:52 - Configural frequency analysis (CFA) overview 06:38 - Practical applications of CFA 09:18 - How to learn CFA 11:40 - Dr. Stemmler's experience visiting Penn State

Speaker 1: Methodology Minutes is brought to you by The Methodology Center at Penn State. Your source for cutting edge research methodology in the Social, Behavioral and Health Sciences. Michael: Hello and welcome to Methodology Minutes. Our guest today is Dr. Mark Stemmler. Mark is a visiting scholar this fall at the Methodology Center.

He's spending 5 weeks here to teach a 1-credit course in Configural Frequency Analysis. Mark is visiting from Bielefeld University in Germany where he is Professor of Psychological Methodology and Quality Management.

Mark Stemmler: Hi, Michael.

Michael: Hello and good morning and welcome to Methodology Minutes. Thanks for being here with us today.

Mark Stemmler: Thanks for having me over.

Michael: You're welcome. It's been a very fast, quick, a whirlwind 5 weeks I'm sure for you so you've been very busy and I thank you for spending the time this morning on your last week here-

Mark Stemmler: Yes, that's true.

Michael: In the US with us to take some time out. We appreciate it. I guess I'd first of all just like to start by asking you a little bit about your current position in Germany and maybe some background on your research interests to lay the stage for how you came here to The Methodology Center.

Mark Stemmler: As you mentioned, I'm a Professor of Psychological Methodology and Quality Management but I am also at the moment the Chairman of the Faculty of Psychology and Sports Science and I am also a member of the Center for Statistics at Bielefeld University.

My research interests are actually 2 kinds of different fields. I am interested in methodology, especially longitudinal data analysis and categorical data analysis but I am also a Developmental Psychologist. I am interested in the social behavior of children and adolescents.

Michael: As far as your connections to The Methodology Center, how did you come to visit us? Was there specific collaborations that started this process or other specific experiences?

Mark Stemmler: I graduated from Penn State and the College of Health and Human Development. By then I had a minor in Statistics and I always was interested in methodological issues.

of 8 I tried to keep in touch with the College of Health and Human Development throughout my working life. First in 1998, I invited Linda Collins, the Director of the Center over to give a talk on Latent Transition Analysis because I organized a meeting on Longitude Data Analysis.

It was a small meeting in Nuremberg. I visited Penn State myself twice, to visit the Prevention Research Center of Mark Greenberg so I have been in touch.

Michael: A long tradition it sounds like, of you and Penn State working together and knowing each other.

Mark Stemmler: Yeah, I have very good memories of my Graduate Program. My son was actually born here in State College 18 years ago. I have fond memories of this town.

Michael: Nice. Good, so it's good to come back and have the personal as well as the professional links.

Mark Stemmler: That's correct.

Michael: Good. Can we talk a little bit about the class that you were teaching this fall? The Configural Frequency Analysis in a little bit more detail. First of all, just a general description of what this method is and is used for. Those types of details, can you provide us?

Mark Stemmler: Configural Frequency Analysis or how we call it, CFA was invented by Gustav A. Lienert in 1969, actually. He gave a presentation on this method at the German Conference and I learned about CFA from Alexander Von Eye who was a Professor in the 90s when I was a student here.

Alexander Von Eye was a student of Gustav A. Lienert. CFA is basically a tool for the analysis of categorical data for contingency tables.

Michael: Much like LCA.

Mark Stemmler: Exactly. Yes, yes. It's related to LCA. It's a person oriented approach instead of a variable oriented approach. You don't look at means. You look at people, objects, animals, grouping together with certain patterns or configurations.

of 8 Its closest statistical relative is log-linear modeling. In log-linear modeling you try to fit the data to your model. In CFA you're doing a residual analysis and so you look where the data does not fit.

You look at certain patterns or cells, configurations that occur more often than expected. You look at over frequented, Wickens called it outlandish cells. Outlying cells.

If you have a certain cell where people, objects lump together we call this a type. It's an outlandish cell but it's also interesting to look at antitypes. Those people, combinations that occur less often than expected.

How I instructed my class is to want to show them that it's not something strange but it's a ... I have one session on CFA and log-linear modeling. I have one session on CFA and LCA, Latent Class Analysis. I want to show, whenever you have categorical data and you look at the structure of the data, CFA gives you more insight into the underlying structure.

Michael: Can I go back and ask you a little bit more about the types and antitypes that you mentioned? Could you provide an example maybe that would give a concrete example of a type or antitype or a research question that might be asked in that framework?

Mark Stemmler: One advantage of CFA is that you are independent of any distribution assumptions, basically. You don't require normal distribution and you can actually work with a relatively small N. I am doing Data Consulting for the Children's Clinic at The University of Erlangen, Nuremberg.

They have data of newborns. They have different complications, they had very low birth weight, they had seizures, they needed oxygen so different treatments. Then they have data on their cognitive development in kindergarten.

Whether it's normal or below average, so what they want to see is what different patterns, configurations, lead to a normal development? Is it a problem if your child has low birth rate and seizures and needed oxygen or is it okay?

You look at patterns and you see and you know what kind of children more often than expected develop normally. You look behind the pattern. That's interesting for them to see what are predictors for a normal development, what are predictors for maybe a detrimental development.

of 8 Michael: That's a pretty good example I think, of one situation that this could be applied. Are there other typical uses of this method that you would say is used in Developmental Psychology more or is it less frequently used in certain areas?

Mark Stemmler: The one advantage is that you could look at ... You go beyond the bivariate analysis. You can look at higher order interactions at the same time. That's a very good-

Michael: Especially with the smaller data samples you mentioned.

Mark Stemmler: Exactly, yeah. There is this famous Meehl's Paradox. Paul Meehl who wrote an article in the 50s about this paradox. Sometimes you have zero bivariate associations but in fact they are higher order interactions which you would never detect if you look only at correlations.

Michael: We all know the limitations of small sample sizes that if you are looking for p-value you use 05, the magical number so this may allow you to look at those higher order interactions and detect some of those patterns.

Mark Stemmler: Exactly, yeah.

Michael: How would someone who is interested in learning this method go about it? What software is available for conducting a Configural Frequency Analysis?

Mark Stemmler: Yes, actually there is a, what we call a shareware or freeware. It's a program written by Alexander Von Eye which can be downloaded for free from his website. He's at Michigan State University. There is an R- package. A CFA R-package and actually there is a SAS macro that can be used.

Michael: Good. You mentioned that it's closely related to log-linear analysis. Does someone need to be very adept at log-linear analysis to conduct this CFA?

Mark Stemmler: No, but it would help. I mean, if you are knowledgeable of log-linear modeling, what are actually main effects or what interactions in terms of configurations, or in terms of contingency tables that would really help.

Michael: There is probably a nomenclature or language that's maybe used that is helpful to understand to do the CFA.

Mark Stemmler: It's actually not very complicated. It's very easy to learn.

of 8 Michael: Good, good. Can you point to any resources specifically? Books or some articles that one could find?

Mark Stemmler: Yes, actually there is a new textbook by Alexander Von Eye. His older version was from 2002 and actually in Germany we have a Journal, what you call Psychology Science and it's from the Pabst Publishers.

We actually have published at least 3 special issues on Configural Frequency Analysis. Myself, I have published a special issue in memorial of Gustav A. Lienert who died in 2001. Those things are available in English and most of the articles can be downloaded from the Pabst Publishers website. It's P-A-B-S-T.

Michael: That sounds very interesting. I think that's something that I believe a lot of our listeners would be interested in learning more about. I certainly have not used the method but it sounds very exciting and I think I'd like to learn more about it. It sounds like it's approachable.

Mark Stemmler: It is and it's very useful and I'm glad that I was able to learn it from Alexander Van Eye.

Michael: Speaking of learning, that's a nice segue to our next topic. Just can you talk a little bit about your experience here at Penn State teaching the 1- credit course? How did it go and what types of students were attending and those types of things?

Mark Stemmler: What I learned is that if you are teaching a 1-credit course, you get a small number of students but they are highly, highly motivated so it's really nice. I have to admit that I was here to teach them but based on their questions I was also learning a lot.

Michael: Great.

Mark Stemmler: I enjoyed it very much.

Michael: Good.

Mark Stemmler: They make me think and look for alternatives. When I came here I had only Alexander Von Eye's program, they wanted me to ... Because they used SAS a lot so I was looking to SAS Macro.

Michael: That's how you were able to find out about those other resources available. Great, great. What other activities were you involved with while you were here in your 5 weeks?

of 8 Mark Stemmler: Like every presentation that you brown bag.

Michael: Yes.

Mark Stemmler: Which I enjoyed very much because very nice atmosphere. People like to talk and ask many questions but they're very nice and I am a member of Donna's Cause and Effects Modeling Group.

Michael: Oh, good.

Mark Stemmler: Let's see how we manage to meet on a monthly basis with me being in Germany. Maybe through Skype or something.

Michael: You are going to continue that collaboration-

Mark Stemmler: Yes.

Michael: With Donna for her component. That's great. That's good. On the personal side, how have you enjoyed your visit here to State College this time around? Have you had a chance to do any fun activities?

Mark Stemmler: Yes, yes actually I went to 2 football games which was a lot of fun. I walked up on Nittany Mountain this Monday and I have to say this center is a great center. You will meet knowledgeable people.

There are lots of people who I can ask questions so I am even thinking of coming back in 2 years and spend a Sabbatical semester here.

Michael: Great.

Mark Stemmler: Thanks also to Linda Collins for inviting me.

Michael: It sounds like you had a very good experience. I know that everyone here has enjoyed having you. I have enjoyed having you here this morning for the podcast. I really appreciate you taking the time and thank you very much.

Mark Stemmler: Thank you very much.

Speaker 1: You have been listening to Methodology Minutes. Brought to you by the Methodology Center at Penn State. Your source for cutting edge research methodology in the Social, Behavioral and Health Sciences. This podcast is available on iTunes and at methodology.esu.edu.

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