# Tagged Questions

IBM SPSS Statistics (formerly SPSS, i.e. "Statistical Package for the Social Sciences") is a proprietary cross-platform general-purpose statistical software package. [For SPSS Modeler, use 'spss-modeler' tag.]

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### Significant output in Levene's test for equality of variances in MANOVA; what to do?

I want to perform a MANOVA in SPSS as follows: i have a independent variable that consists of three groups (- of which the group sizes are not equal), and six dependent variables. When checking the ...
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### Interpretation of mixed model with repeated measures

I have performed the following experiment: Two genotype groups of two different ages were monitored in the presence of three drugs one after the other. So, each subject after a control period received ...
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### GEE (or GLMM) in SPSS: Interpreting outputs and model selection

I am attempting to analyze my (experimental psych) data in SPSS, and I have a few questions regarding the kind of analysis I should be using (GEE or GLMM), how I should be interpreting the output, and ...
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### How to assess mediation effect in multinomial logistic regression?

I wonder if it possible to include a mediation effect in multinomial logistic regression. I have a categorical (3 categories) outcome variable and four predictors (all continuous). I expect one of the ...
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### Identical mixed models in SPSS and R nlme, with different degrees of freedom. Which to trust and why?

I am analyzing a multilevel dataset with an AR(1) error structure and random intercept and slope. I fit what I believe is the exact same model in SPSS and R- my coefficients and standard errors are ...
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### Clarifying which ANOVA to use

This is a bit complex so I'll try to explain as succinctly as possible. I'm doing thesis testing and I need to make sure I'm getting it right! Basically, all participants underwent a decision task, ...
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### Between groups two way ANOVA - time points as an IV

I'm looking to carry out a between groups two way ANOVA and need some help. The first IV is the group (two levels - control and intervention) and the second IV is behaviour across time (behaviour pre-...
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### chi square for trend - SPSS

I have followed fourth-year university students for ten years, recording their attitudes to a particular lecture. The outcome is binary (good-bad). I have 10 rows and 2 columns, meaning year and ...
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### Fixed parameter estimates of parent factors in a nested design

Summary: What is happening with parameter estimates of factors that are the 'parents' of nested factors? Data: My analysis involves testing the effect of different parameter settings for automatic ...
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### Q: Exploratory factor analysis in R

I am trying to do an exploratory factor analysis (EFA) in R with oblique (promax) rotation. From Wikipedia, In oblique rotation, one gets both a pattern matrix and a structure matrix. The ...
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### SPSS: Pearson's r not significant but confidence intervals do not include 0

I have calculated the value of Pearson's r between two variables in SPSS, two tailed. Sample size is 81. The r value is -.21. The p value is .06. When I compute the 95% confidence intervals using ...
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### Interpret the pairwise comparison plot from SPSS

For my user study, I am trying to find out to what extent people prefer to move by foot. They had the option to rank their preference for 'walking', 'jogging' and 'running' for a several amount of ...
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### Does it make sense to plot train and test results on a common ROC graph?

I am building a model using SPSS with 80% of my data. I can plot a ROC curve for both the training set and separately for the test set. I can´t find a way to plot both on the same graph. Since both ...
620 views

### Find out if there is a way to create BMI weight category variable

I am working on a project and have to find a way to break my data into percentiles. The variables that I already have are gender, age in months and BMI. If I am able to calculate the percentile that ...
983 views

### Binomial logistic regression in SPSS using survey weights

I am running a logistic regression in SPSS with a sample that uses survey weights. The sample size is 1000 and the weights are along the lines of .86 or 1.23 depending on the case. I am using the ...
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### Is it possible for my mixed model results to be the same as those for a repeated measures ANCOVA? Why don't I get the same results? SPSS

The experiment: Two groups of children perform tasks with three levels of difficulty at two different time points and brain activity is measured. All of the children perform all of the tasks and do so ...
821 views

### What does the Scale parameter mean in linear regression?

I have started to use the GENLIN procedure in SPSS more than any of the specific dialogues, but I don't understand the Scale parameter or why it has the effects it ...
627 views

### Split-split-split plot cross-over design… is this even possible?

I'm doing statistical analysis on a psychology study I ran a short while ago, and I'm starting to think that I've designed myself into a corner. In the study, we measured participants' pointing ...
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### How do I estimate a repeated measures ANCOVA in R and SPSS?

I'm currently running a perception experiment: DV: error (this in degrees- how much an observer was away from the real answer) IV: the time bin (5 levels) in which the unique stimulus appeared IV2:...
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### Time series with 3 factors from different sources

I've been asked to try to do a preliminary 'meta-analysis' of some data, but while comfortable with maths I don't have much experience with stats. I'm hoping to get some feedback with what I have ...
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### Interpretation of continuous by continuous interaction in binary regression model

I'm performing binary logistic regression in SPSS; y is dichotomous variable; and both Xs are continuous variables. I performed three models and I have troubles interpreting model with both ...
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### comparing survey responses

I have requested 30 participants to answer the same question about 100 images: "How easy is it for you to recognize this image?" on a scale from 0 to 100, where 0 is easy and 100 is difficult. I want ...
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### Can Cochran's Q test take a 3 level nominal variable as the response (instead of 2)?

I conducted a study using within-subjects (repeated measure) design for collecting nominal data. I have been reading a lot closet I get for a suitable test is Cochran's Q test since I have repeated ...
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### How to incorporate weight into linear regression in SPSS

I would like to know the proper procedure to execute weighted linear regression analysis. I have come across different tutorials about weighing in SPSS, but can't distinguish which is appropriate. ...
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### DFA in SPSS: Sorts effectively, but Box's M is still 0.000. Is the analysis worthless?

I am a geologist attempting to apply the discriminant function analysis to surface features I have mapped in ArcGIS. At the moment I have 4 dimensionless sorting variables calculated for each feature, ...
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### In a linear mixed model what does the F value represent?

I am examining the output of my linear mixed model in SPSS and need to decide how to report my findings. I was considering just reporting the p-values. However, my supervisor wants me to provide more ...
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### Computation of factors after factor analysis

I have run a principal axis factor analysis and I want to form scales for each factor. To be more specific, after having run the FA, I would like to select all items that load in a specific factor and ...
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### What is the best method to statistically test two areas?

I am investigating the difference in childhood obesity rates between Dudley and Brighton & Hove. These areas have similar deprivation rates but very different childhood obesity rates. I am looking ...
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### Comparing measurements obtained from >2 devices (Bland-Altman, Tukey mean difference plot)

I would like to compare different measurements in regard to agreement. Quite often this is done using a Bland-Altman plot (also called Tukey mean difference plot) in medical literature. What I would ...
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### Interpreting interaction between time and time-varying predictor in mixed models

I have measured the DV and predictor at 2 timepoints in a single group, and am using the MIXED procedure in SPSS. I want to see whether change in the DV over time is predicted by change in the ...
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### Test analysis - repeated measures

I lack the experience and can't find an answer anywhere at the moment. The situation is as follows: I would like to test a new device measuring the heart rate of a patient. For this, I have observed ...
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### Nominal or ordinal?

I've got several variables in a dataset of which I'm not really sure what type of data they are: nominal or ordinal. Context: the variables are part of a dataset in which each case a student. Of ...
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### Logistic regression: Absolute values for P

I am stuck with a problem (actually two problems). I have a dataset of about 150 cases and 30 or so dichotonous (yes/no) parameters. I selected 6 parameters (after literature study and crosstabs) for ...
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### Why would standardized betas be high (e.g. .66) but non-significant in moderated regression?

Running a moderated regression using PROCESS macro in SPSS (issue replicated by running the same moderation using mean-centered variables in SPSS linear regression command box), I am finding that the ...
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### Correlating aggregated values between groups

I am currently analysing data from household surveys in 27 Indian villages in 7 states, with about 30 cases in each village (807 in total). The aim is to find relationships between various factors and ...
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### Polynomial contrast in mixed anova with type III SS

I'm trying to replicate SPSS output in R for a mixed ANOVA with a polynomial contrast to test a linear trend. I fitted a mixed ANOVA in R (see code below), but I can't figure out how to get the ...
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### Methods for measuring snowball effects in a “complete” longitudinal dataset

I'm looking for ways to test for "cumulative advantage" effects in a longitudinal dataset (see image) I guess the data set is principally similar to this: http://www.caldercenter.org/whatis.cfm , ...
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### How to: repeated measures anova and Friedman's test with multiple imputations for missing data

I have a study where patients were measured pre-operatively (time_pre), post-operatively (time_post) and long-term follow-up (time_lt). I have 60 subjects. Data consists of: 5 scale variables (1-100)...
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### Assessing Cannibalization, intervention of new mobile app on monthly sales

I am a beginner in statistics and looking for suggestions from you all on the approach for one of my study. For my study, there is a company which sells products via its online website (lets call it ...
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### Obtaining the Standard Error of Weighted Data in SPSS

I'm trying to find confidence intervals for the means of various variables in a database using SPSS, and I've run into a spot of trouble. The data is weighted, because each of the people who was ...
521 views

### Contingency tables, Chi-Squared analysis and next steps in R

I'm hoping one of the more experienced R programmers/statisticians out there can help me with something, or explain why what I'm trying to do is stupid :-) In the past, I've done analysis of survey ...
403 views

### How does my questionnaire analysis plan sound?

I will soon have the results of a questionnaire that I have carried out, and I have made a plan on how I will analyse the data. I was hoping that someone could comment on my plan to advise me. About ...
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### How to code and analyze skiped questions with SPSS

sorry if my question may seem rather silly, but I'm not well up on statistics and need a piece of advice. I have some cases in my dataset where respondents have abandoned the survey half-way, so I ...
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### Composite Scores and Standardized Composite Scores t test

I have a set of survey data related to 20 survey questions. Each of these questions represent a variable (Q1, Q2,......
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### How to compare 37 dichotomous variables (lab tests) to 31 dichotomous variables (diagnosis)

I've constructed a database based on chart review of patients. Patients had a variety of tests performed (37 different types, which were either positive, negative, or not performed aka 1/0/blank - I ...
444 views

### Model comparison in SPSS

I have two models with 24 variables in each. I want to see how adding an extra variable (the variable in study) affects the outcome. I used generalised linear mixed models for both models.(GENLINMIXED ...
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### Which model for data which has within-effects, between effects and non-parallel lines

My data (Panel, 19 countries, 7 years, ordinal outcome variable) has within-effects (countries over time), between effects (between countries) and it seems as if the slope of lines (test of parallel ...
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### If I compare conditions within two preexisting groups is that a quasi-experimental design?

I have two groups of participants, one group of psychosis patients and one group of controls. All of the participants complete a computer task that has three different conditions. So, I want to make ...