Categorical data can take on a limited (usually fixed) number of possible values called categories. Categorical values "label", they do not "measure". Nominal and dichotomous/binary scale types are categorical. Some people consider ordinal scale categorical too.

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Glmer model won't run all factor levels due to multicolinearity

I have a repeated measures design in which I test multiple individuals each with three different 20 second playback stimuli. I used 6 different playback orders in which each stimulus was played either ...
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36 views

Is there a way to do a statistical test if an independent variable has only 1 level?

I have a repeated measures design in which I tested multiple individuals with three different sounds (playbacks). The playbacks were 20 seconds in length and I recorded 1) how individuals responded ...
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8 views

Looking to quantify improvement across categorical data

Have two sets of observations First data set - is measures success of an activity after minimal training Second data set - measures success of the same activity after significant training. The ...
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2answers
94 views

Does triple interaction need to include all main effect variables?

I have a triple interaction: AxBxD, where A and B are continuous variables and D is a dummy. My regression is Y = A + B + AxB + AxD + AxBxD In this case, do I HAVE TO include BxD also? In theory here ...
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26 views

Get groups in time series with categorical data in R for use in gts

I have sales data organised in a table with 6 columns (4 for the location and type data, and 2 for the dates and the quantity sold), and 24 rows for each category representing the sales over 24 months ...
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34 views

Gower's Distance issue

So, I'm relatively new to using Gower's distance to do cluster analysis. I've done some research on this for a little while and like the fact it can incorporate categorical variables. To get a better ...
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22 views

How does turning categorical variables into dummy variables affect ANOVA results?

I'm running a multiple linear regression with (amongst others) several categorical explanatory variables. My categorical variables are factors with several factor levels. For example, variable $x_1$ ...
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1answer
24 views

Inter-rater reliability for unordered categorical data

I have some content analysis data that consist of unordered mutually exclusive categories as rated by two coders. What are useful approaches towards assessing inter-rater reliability for these data? ...
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9 views

Code to create interacting dummy variable [migrated]

I'm very new to R and am trying to interact my dummy variable with an explanatory variable and don't know how to do this. Apologies if I've not formatted this the right way but I'm new to this site as ...
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1answer
27 views

dummy variables, interaction with continuous variable, and variable selection

I want to predict shop sales from a set of independent variables which consists of shop attributes like floor space, no. of stuff of a specific store (continuous variables) and also location of the ...
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1answer
51 views

Please help with an appropriate type of regression to obtain numerical result (SPSS) with categorical data

Please help me to figure out the right approach for fairly straightforward task. Let say, we asked respondents to state 3 most important attributes (over ten) for the one product. Answers were coded ...
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6 views

How to compare factor levels in an averaged model

I'm running an analysis of my thesis data where I measured biodiversity, associated environmental variables and 2 categorical factors (region with 3 levels and garden type with 4 levels). I'm using ...
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13 views

MANCOVA with categorical moderator - it is possible?

I have two continuous variables which are my DEPENDENT variables and two PREDICTORS which are continuous too, but I need to test with MANCOVA an interaction of a third variable (moderator), which is ...
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1answer
26 views

What should can I do with some items loadings on unexpected construct?

I conducted a Principal Component Analysis to reduce the items and dimensions. But some items loaded on unexpected construct and the items have a low face validity with the construct. Is that a ...
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1answer
30 views

Problem with Application of Pearson's Chi-Squared test

I'm using Pearson's chi-squared test to to compare the knowledge of two independent groups on knowledge about contact lens. But the number of respondents in group A is n = 200 and the number of ...
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34 views

Modeling a national dataset at a lower level of census geography

I want to build a model from a set of a over 100000 individual survey responses. Then, from the distribution of new responses (not found in the training set) on a subset of questions from the survey, ...
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7 views

Parameter Tying: Using observations of one category to lift estimates of baseline ability

I am trying to model an individuals' ability to perform one of several similar tasks. We would like each individual's performance to reflect three factors: the mean ability of the general population, ...
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20 views

Which statistics to use and how to organize data

I have a categorical dependent variable, namely the answer that participants gave to a series of items. The answer can be "yes", "no" or "maybe" (x 54 items per participant). There are two independent ...
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2answers
47 views

Can categorical variables be treated as count data?

In a questionnaire study, I asked for the frequency of certain behaviors using a 5-point scale. Originally, I planned to treat it as categorical, however, distribution of the answers (N=1000) turns ...
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0answers
36 views

Fast Algorithm for Bayesian Measurement Model

I want to estimate a Bayesian Measurement model. That is I am concerned with the rating of each judge $j$ of the value of some trait $z$ for each observation $i$. Not all raters will have rated each ...
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3answers
66 views

Negative Binomial Regression?

I have a dependent count variable that measures the number of days spent in a hospital (LOS) for a group of patients who received two different medical interventions upon hospitalization. I'm trying ...
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1answer
77 views

How can logistic regression have a factorial predictor and no intercept?

I tried a regression in the form ${\rm logit}(Y) = {\rm coefficient}\times X + 0 + e$, where $Y$ is a binomial variable and $X$ is a factor variable with $n$ levels. I noticed that removing the ...
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1answer
36 views

Dummy for multivariate time series regression (intercept and slope effect)

I am trying to understand if it is possible to use dummy observations in time series analysis, to split the effect of two or more groups in the model. Assume that we have n observations for 4 ...
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31 views

What statistical technique could I use to see if gender effect exists in this scenario?

Suppose I give 6 short stories (of word length varying from 200 to 400),and ask N=100 students about which one (e.g., story #1, #2,..., #6) is their favorite story (see below table). Some data are ...
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2answers
94 views

What does “Virgin Data” mean?

I am using RTextTools, which has a function to create container with following syntax: create_container(matrix, labels, trainSize=NULL, testSize=NULL, virgin) ...
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14 views

Multivariate Bernoulli, Covariances for Categorical Data

I need to find outliers in multidimensional, categorical, 1-hot encoded, binary data. Data might look like, 0,1,1,0 1,1,0,0 1,1,1,0 0,1,1,1 0,0,1,0 I toyed with ...
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16 views

Analysis to assign a categorical var to a ordinal

I have a categorical outcome with > 2 levels and a categorical predictor with many levels. Which model can I use to assign to each predictor level the probability of being in one of the classes of ...
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1answer
20 views

ordinal classification using C5.0

My question is about machine learning to predict ordinal variables. Most ML models for classification that I have seen do not make any assumption about the order of different categories. I can see ...
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1answer
57 views

Correlation between a numeric and factor in R [duplicate]

I'm new to R and I'm trying to find the correlation between a numeric variable and a factor one. I have a data frame with the following 3 columns: 1. nr of clicks (range 0:14) 2. response (1= "YES", ...
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18 views

Scaling data constrained to be varying between a floor and ceiling set of values

I have data that range continuously between the values of 0 and 2, usually somewhere in between close to 1 on average. 0 is a "floor" and 2 is a "ceiling." The data describe more than one group of ...
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1answer
27 views

Rearrange regression equation that includes a dummy variable

This is my regression equation: $10 = 5.44 + 0.26X_1 - 3.19X_2$ $X_2$ is a dummy predictor with two levels. Assume that the value of $X_2$ is 1 therefore regression equation is: $10 = 5.44 + ...
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1answer
32 views

Can a factor be used as Y variable? Best test?

I have many plant populations of the same species sampled (around 100). What is measured is an allele on one gene, that can be A,B or C. This is what I would like to use as Y variable. Then I have the ...
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2answers
32 views

Ordinal or nominal

I designed a questionnaire regarding teacher readiness to conduct / perform certain tasks other than teaching in the classroom. One of the items included is the period of service of the teacher. Here ...
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21 views

Accuracy of rpart for categorical

Below is an example of fitting categorical data using rpart. But how to compare the predictions from rpart with the actual data? Also, is it possible to draw a ROC curve for the testing and training ...
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41 views

Post-hoc Chi Square Test for Pairwise Comparison of 3 Groups

I am trying to do something that in my mind is probably simple and I'm probably just blanking on it. I am using Stata to compare 3 groups on a categorical variable. So, as an example, I would be ...
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65 views

proving regression with dummy variables gives same estimates as separate models

Let ($x_{i1}$, $x_{i2}$, ..., $x_{id}$, $y_i$), $i = 1,..., n$ be an i.i.d. multivariate sample and furthermore assume each observation belongs to one of possible $K$ categories. Assume for each ...
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22 views

Which kind of analysis could be made to associate a set of genes to clinical values?

I have a set of 5 genes that can be mutated or not, so therefore are intended as dichotomous yes/no vars. I want to identify the effect of the mutation of this genes on a continuous response var. The ...
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1answer
27 views

SPSS logistic regression. categorical --> dummies

All our variables (question asked to students in our questionnaire) given by school are answered by: 1) very important 2) important 3) unimportant 4) vert unimportant we want to use these variables ...
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1answer
58 views

Generate random correlated categorical variables

Lets say I want to generate 100 observations of 2 likert scaled, normally? distributed variables with 10 categories (1-10) and a pearson correlation of f.e. ~0.8. I am aware that using pearson ...
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1answer
73 views

Chisquared on categorical data or a Wilcoxon test on the counts hereof?

This question is related to a question I had in R on SO here The background of my question is fairly simple. I was given two "databases" in the form of data.frames ...
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1answer
28 views

Calculating CI and SD for individual regression lines from a multiple factor glm

We have 2 correlated variables and a lot of binomial factors (around 200), here illustrated with just $f1$ and $f2$: ...
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1answer
27 views

Computation of Yes/No question and 7 point Likert scale into new variable

I could not find an answer to this specific question on the forum so ill make a new post. Thanks a lot for helping! I have 5 Yes/No question, and 5 7-point likert scale items (that each corresponds ...
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1answer
59 views

How to regress two categorical variables

I'm not looking for a detailed answer, just some pointers towards possible things I could read to better understand this problem. Let's say that we have a survey that asks two questions, $X$ and $Y$. ...
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1answer
56 views

Using year fixed effects on data with yearly observations

I have a panel data set with yearly observations of various firms over a period of 5 years. I am running a fixed effects model in Stata using xtreg. Is it ...
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1answer
17 views

Mean comparison of two categorical variables

I'd like to compare people's perception of safety at a certain location [which is a categorical variable on a scale of 1-10, with 1=feel very unsafe & 10=feel very safe] before and after being ...
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11 views

Testing for a 3-way interaction between a within-subjects factor, a continuous IV and a categorical IV in SPSS

I'd like to test whether the moderating effect of a (continuous) personality variable on the effect of an experimental manipulation differs between conditions. Does anyone know how to go about this in ...
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14 views

To demean or to use dummies in maximum likelihood

I have a dynamic panel data with T=20 and N=1500 and I use a maximum likelihood estimation (more precisely its a VAR). Using a dummy variable approach to account for fixed effects introuduces an ...
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3answers
271 views

How would you categorize / extract information out of job descriptions?

I have a bunch of job descriptions entered by users. There are all sort of misspells and bad data. i.e: ...
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17 views

using a dummy to indicate zero values of a overdispersed continuous predictor variable [duplicate]

I have a predictor variable that has many zeros. The predictor variable is simply a count of the occurrences of some behavior. The zeros are qualitatively meaningful. I'd like to use a log ...
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1answer
42 views

Defining NULL group for dummy variables

I am quite new in R and am on a stage of running a regression model there. The approach we have chosen is linear regression with dummy variables. As far as my knowledge and experience go when using ...