Questions tagged [spss]
IBM SPSS Statistics is a statistical software package. Use this tag for any on-topic question that (a) involves SPSS either as a critical part of the question or expected answer and (b) is not just about how to use SPSS.
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Python as a statistics workbench
Lots of people use a main tool like Excel or another spreadsheet, SPSS, Stata, or R for their statistics needs. They might turn to some specific package for very special needs, but a lot of things can ...
170
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4
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When is R squared negative? [duplicate]
My understanding is that $R^2$ cannot be negative as it is the square of R. However I ran a simple linear regression in SPSS with a single independent variable and a dependent variable. My SPSS output ...
72
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8
answers
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Is PCA followed by a rotation (such as varimax) still PCA?
I have tried to reproduce some research (using PCA) from SPSS in R. In my experience, principal() function from package psych ...
51
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7
answers
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Why is "statistically significant" not enough?
I have completed my data analysis and got "statistically significant results" which is consistent with my hypothesis. However, a student in statistics told me this is a premature conclusion. Why? Is ...
43
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1
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Doing principal component analysis or factor analysis on binary data
I have a dataset with a large number of Yes/No responses. Can I use principal components (PCA) or any other data reduction analyses (such as factor analysis) for this type of data? Please advise how I ...
38
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4
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Difference between binomial, negative binomial and Poisson regression
I am looking for some information about the difference between binomial, negative binomial and Poisson regression and for which situations are these regression best fitted.
Are there any tests I can ...
35
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5
answers
85k
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Fisher's Exact Test in contingency tables larger than 2x2
I was taught to only apply Fisher's Exact Test in contingency tables that were 2x2.
Questions:
Did Fisher himself ever envision this test to be used in tables larger than 2x2 (I am aware of the tale ...
34
votes
1
answer
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Best factor extraction methods in factor analysis
SPSS offers several methods of factor extraction:
Principal components (which isn't factor analysis at all)
Unweighted least squares
Generalized least squares
Maximum Likelihood
Principal Axis
Alpha ...
28
votes
3
answers
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Choice between Type-I, Type-II, or Type-III ANOVA [duplicate]
We have a dataset with three variables (dV: self-reported measure on scale 1-5, assumed to be metric; iV1: factor with 4 levels; iV2: factor with 8 levels). We are interested whether the dV differs in ...
24
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1
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After bootstrapping regression analysis, all p-values are multiple of 0.001996
I'm running various multiple regression analyses in SPSS 27, and with those that are not bootstrapped, the p-values vary such that I do not find the same p-value twice within a regression (e.g., the p-...
24
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1
answer
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Methods to compute factor scores, and what is the "score coefficient" matrix in PCA or factor analysis?
As per my understanding, in PCA based on correlations we get factor (= principal component in this instance) loadings which are nothing but the correlations between variables and factors. Now when I ...
23
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2
answers
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CHAID vs CRT (or CART)
I am running a decision tree classification using SPSS on a data set with around 20 predictors (categorical with few categories). CHAID (Chi-squared Automatic Interaction Detection) and CRT/CART (...
23
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2
answers
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How to cluster time series?
I have a question about cluster analysis. There are 3000 companies, which have to be clustered according to their power usage over 5 years. Each company has values for every hour during 5 years. I ...
20
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4
answers
29k
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Visualizing Likert responses using R or SPSS
I have 82 respondents in 2 groups (43 in Group A and 39 in Group B) that completed a survey of 65 Likert questions each ranging from 1 – 5 (strongly agree - strongly disagree). I therefore have a ...
19
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6
answers
8k
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Interpreting discrepancies between R and SPSS with exploratory factor analysis
I am a graduate student in computer science. I have been doing some exploratory factor analysis for a research project. My colleagues (who are leading the project) use SPSS, while I prefer to use R. ...
16
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2
answers
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How to get pooled p-values on tests done in multiple imputed datasets?
Using Amelia in R, I obtained multiple imputed datasets. After that, I performed a repeated measures test in SPSS. Now, I want to pool test results. I know that I can use Rubin's rules (implemented ...
15
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3
answers
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My distribution is normal; Kolmogorov-Smirnov test doesn't agree
I have a problem with the normality of some data I have:
I've done a Kolmogorov test which says it isn't normal with p=.0000,
I don't understand: the skewness of my distribution =-.497, and the ...
15
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3
answers
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How to handle with missing values in order to prepare data for feature selection with LASSO?
My situation:
small sample size: 116
binary outcome variable
long list of explanatory variables: 44
explanatory variables did not come from the top of my head; their choice was based on the ...
15
votes
3
answers
154k
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How to deal with non-binary categorical variables in logistic regression (SPSS)
I have to do binary logistic regression with a lot of independent variables. Most of them are binary, but a few of the categorical variables have more than two levels.
What is the best way to deal ...
15
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3
answers
1k
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Predicting variance of heteroscedastic data
I am trying to do a regression on heteroscedastic data where I'm trying to predict the error variances as well as the mean values in terms of a linear model. Something like this:
$$\begin{align}\\
y\...
13
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5
answers
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Stepwise logistic regression and sampling
I am fitting a stepwise logistic regression on a set of data in SPSS. In the procedure, I am fitting my model to a random subset that is approx. 60% of the total sample, which is about 330 cases.
...
13
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5
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Multiple imputation for missing values
I would like to use imputation for replacing missing values in my data set under certain constraints.
For example, I'd like the imputed variable x1 to be greater ...
13
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4
answers
13k
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Comparing logistic regression coefficients across models?
I've developed a logit model to be applied to six different sets of cross-sectional data. What I'm trying to uncover is whether there are changes in the substantive effect of a given independent ...
13
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5
answers
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Better Classification of default in logistic regression
Full Disclosure: This is homework. I've included a link to the dataset ( http://www.bertelsen.ca/R/logistic-regression.sav )
My goal is to maximize the prediction of loan defaulters in this data set. ...
12
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3
answers
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Can I use multiple regression when I have mixed categorical and continuous predictors?
It looks like you can use coding for one categorical variable, but I have two categorical and one continuous predictor variable. Can i use multiple regression for this in SPSS and if so how?
thanks!
12
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1
answer
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Displaying Ordinal Data - Means, Medians, and Mean Ranks
I have some ordinal data that is not normally distributed, so I decided to do non-parametric testing using the Mann-Whitney U Test. I am looking at differences between groups for seven scores - these ...
11
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2
answers
15k
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Should I report non-significant results?
I've run a Kruskal Wallis test, and for some of the questions the p value is not significant. Would I report this in the same way as if it was significant, stating the df, test statistic and p-value? ...
11
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3
answers
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Is it acceptable to have only two (or less) items (variables) loaded by a factor in factor analysis?
I have a set of 20 variables that I have put through factor analysis in SPSS. For purposes of the research, I need to develop 6 factors. SPSS has shown that 8 variables (out of 20) have been loaded ...
11
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5
answers
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Calculating eta squared from F and df
I'm trying to compute ANOVA effect sizes from papers that provide an F value without other information. If I understand correctly, the effect size for a single-factor ANOVA is
$$
\eta {2} = \frac{ss_{...
11
votes
5
answers
7k
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Multinomial logistic regression assumptions
What are the proper assumptions of Multinomial Logistic Regression? And what are the best tests to satisfy these assumptions using SPSS 18?
11
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2
answers
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How to correctly treat multiple data points per each subject
I am currently arguing with someoe on how to correctly treat data with multiple measurements for each subject. In this case data was gathered for each subject within a short time for different ...
11
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2
answers
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How do I find correlation measure between two nominal variables?
A survey was made where people chose what they use a certain smiley to represent and entered their country of origin. I have recoded the text responses to numeric.
What form of analysis should be ...
11
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2
answers
39k
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Bonferroni correction with Pearson's correlation and linear regression
I am running stats on $5$ IVs ($5$ personality traits, extroversion, agreeableness, conscientiousness, neuroticism, openness) against $3$ DVs Attitude to PCT, Attitude to CBT, Attitude to PCT vs CBT. ...
10
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4
answers
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Friedman's test is very significant, but its post hoc comparisons (SPSS) are not significant
I ran a non-parametric Friedman's test for my data in SPSS 22 and significantly rejected the null. That would mean that among the $k$ paired samples (3 in my case), there should be detected at least ...
10
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2
answers
21k
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Applying Rubin's rule for combining multiply imputed datasets
I am hoping to pool the results of a pretty basic set of analysis performed on a multiply imputed data (e.g. multiple regression, ANOVA). Multiple imputation and the analyses have been completed in ...
10
votes
2
answers
7k
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Differences in kurtosis definition and their interpretation
I have recently realised that there are differences in the kurtosis values provided by SPSS and Stata.
See http://www.ats.ucla.edu/stat/mult_pkg/faq/general/kurtosis.htm
My understanding is that the ...
10
votes
1
answer
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Justification for low/high or tertiary splits in ANOVA
I have two groups of participants and they all took the same measurements.
When I perform a median split on one of the measurements to test my hypothesis about an interaction, the dependent ...
10
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1
answer
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Is there a standard measure of fit to validate Exploratory factor analysis?
I am modeling Exploratory Factor Analysis in R, Python, Mplus, and SPSS with maximum likelihood method and Varimax orthogonal rotation. However, each software gives different measures of fit and I am ...
10
votes
2
answers
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Understanding repeated measure ANOVA assumptions for correct interpretation of SPSS output
I am investigating whether different reward conditions may affect task performance. I have data from a small study with two groups, each with n=20. I collected data on a task that involved performance ...
9
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5
answers
23k
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Is 0 a valid value in a Likert scale?
I have carried out my pilot study on language learning motivation using a 6 point Likert scale but from 0 (strongly disagree) to 5 (very much agree). I noticed a colleague in his survey used 1 to 6. ...
9
votes
2
answers
7k
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SPSS and Stata output different
I'm Stata-proficient but learning SPSS for my new position. I am using a simple dataset to do very basic regressions and comparing to see if the results are the same. They're not. I'm close, but the ...
9
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3
answers
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How to do post-hoc tests with logistic regression?
I looked at whether participants recycled after being subjected to a given message. There were three groups: a Control group, group A, and group B.
Since my dependent measure was dichotomous (...
9
votes
1
answer
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Building a time series model using more than independent variables
I am working on a project, and I am totally new to statistics. I have sales data for last two years at week level, along with other variables like temperature, holiday (TRUE/FALSE), where holiday are ...
9
votes
4
answers
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Very different results of principal component analysis in SPSS and Stata after rotation
For my PhD thesis I have to do a Principal Component Analysis (PCA). I didn't find it too difficult in Stata and was happy interpreting the results (I know there is a difference between factor and ...
9
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2
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What is the relation between singular correlation matrix and PCA?
Can anyone kindly give me some information about the statement (last sentence) at the end of below definition. What does it mean by "It can be used when a correlation matrix is singular"?
This quote ...
9
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2
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How to test for normality in a 2x2 ANOVA?
Study Design: I showed participants some information about sea-level rise, focusing the information in different ways, both in terms of the time-scale and the magnitude of potential rise. Thus I had a ...
9
votes
2
answers
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How to compare two time series?
I have collected temperature readings for 4 locations on a beach in Cornwall UK using data loggers. The loggers recorded temperature every 15 mins accurate to .1 of a degree (Celsius). The loggers ...
9
votes
2
answers
3k
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Multiple imputation questions for multiple regression in SPSS
I am currently running a multiple regression model using imputed data and have a few questions.
Background:
Using SPSS 18. My data appears to be MAR. Listwise deletion of cases leaves me with only ...
8
votes
2
answers
4k
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How do I test if regression slopes are statistically different?
I have a set of data that is composed of a measured parameter (dependent variable) as a function of time (independent variable), before and after an intervention event.
I have calculated slope and ...
8
votes
4
answers
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Learning how to use a new statistical GUI?
The question is in the header, but I would extend the context a bit.
Next semester I am due to be a teaching assistant (TA) in a course in statistics, where I would need to help sociology students ...