Tagged Questions

0
votes
0answers
17 views

Prepare data for generalized linear regression [migrated]

I want to perform glm for the dataset Titanic in R. I did the following steps to prepare the data and run glm ...
3
votes
1answer
359 views

Ecological mixed data cluster analysis: Transformations required? Use K-means or hierarchical methods?

I am trying to identify habitat types from 85 plots. I intend to do a cluster analysis to identify habitat types, and hope to fit additional plots into the identified clusters. (For context, I took ...
0
votes
1answer
93 views

What assumptions do I need to check to combine levels in a categorical predictor for use in a GLM?

If I have a GLM with a number of explanatory variables, where one is a categorical variable with levels "no treatment" "treatment A" "treatment B" Assuming that it is reasonable to combine the 2 ...
4
votes
2answers
164 views

Categorical or continuous scale for area chart?

I would like to plot the attached income distribution dataset (rendered as an image) as an area chart. As you can see, personal income is divided into 26 intervals of varying width. I also have the ...
0
votes
0answers
210 views

What is the uncertainty when dividing 25 samples into 4 groups? [closed]

In brief, my question is: what is the uncertainty when I divide X data into Y groups? In detail: I have high-resolution count data which I've binned into hourly counts. The result is anything from ...
3
votes
1answer
1k views

Data transformation for Principal Components Analysis from different Likert scales

I have data from a survey comprised of several measures that used different Likert-type scaling (4-, 5-, and 6-point scales). I would like to run a principal components analysis using the data from ...
10
votes
4answers
1k views

How to summarize categorical data?

I've been struggling with the following problem with hopefully is an easy one for statisticians (I'm a programmer with some exposure to statistics). I need to summarize the responses to a survey (for ...
4
votes
2answers
1k views

Is it possible to directly read CSV columns as categorical data?

I need to analyze with R the data from a medical survey (with 100+ coded columns) that comes in a CSV. I will use rattle for some initial analysis but behind the scenes it's still R. If I read.csv() ...
5
votes
1answer
373 views

How can I use optimal scaling to scale an ordinal categorical variable?

In an answer to this question about treating categorical data as continuous, optimal scaling was mentioned. How does this method work and how is it applied?
24
votes
4answers
5k views

Does it ever make sense to treat categorical data as continuous?

In answering this question on discrete and continuous data I glibly asserted that it rarely makes sense to treat categorical data as continuous. On the face of it that seems self-evident, but ...