Involves an unordered, categorical variable, observations of which designate group membership, and generally not quantitative information.

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Diagram for spotting distributions, like “contradicting” results

Let's say we have two results that are related to each other: Result 1 was a questionnaire about food and had two options "I dislike Cake" and "I like Cake". The result is displayed as a ratio: ...
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1answer
23 views

How to process Binomial-Binomial data on SPSS for hypothesis testing?

There are 2 groups of 100 pregnant women: the first are malnourished and the second are well-nourished. A COHORT research is being done on them to determine if malnutrition is a risk factor for low ...
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20 views

Confusion Matrix: nominal vs interval

I want to evaluate my model with help of a confusion matrix. Which measure can I use to consider that my data is interval scaled (eg.:1,2,3,4,5,6,7,8,9,10) ? As I understand the Kappa measure is often ...
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5 views

Finding the differences for nominal data when each participant contributes to more than one cell in the frequency table?

Finding the differences for nominal data when each participant contributes to more than one cell in the frequency table. The point is that I don't have paired nominal data as it is in repeated ...
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29 views

Difference between treatments with binary outcome & sample size estimation - Stata

I have 20 binary outcome variables that I want to test for association with a nominal 'treatment' variable with 6 categories (a,b,c,d,e,f). For the outcome that is significantly associated with ...
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20 views

Transforming nominal attribute to binary for CART

I found the following description regarding model trees for numeric prediction, in which nominal attributes are transformed to binary attributes. Before constructing a model tree, all nominal ...
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10 views

Categorical data and different analyses

Why does categorical data have different tests? I know there are many tests for categorical data such as a crosstabs or Chi-Square but why does the data use different tests?
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7 views

How to test the inter-rater reliability of a nominal coding process that generates ordinal data?

A researcher studying hunger on a tropical island asks respondents, "What did you eat for lunch yesterday?" and the possible choices are "(4) Nothing; (3) a banana; (2) an unripe coconut; (1) a ripe ...
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1answer
45 views

3 categorical IV and 1 categorical DV — what test to use?

Here's my setup: Independent Variables (IV): (A) Task -- values 0 - 6 (order doesn't matter) (B) Viewpoint -- values 0 - 26 (order doesn't matter) (C) Input-device -- values {touchscreen, mouse, ...
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1answer
56 views

Economics: Real vs Nominal Variables

My economic analysis uses OLS with cross-sectional annual data. The dependent variables are defined as x/y where x is a variable (such as trade, debt etc.) and y is real GDP. What if, instead of ...
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27 views

How to enter cross-table data into R for nominal logistic regression? [closed]

I would like to conduct nominal logistic regression analysis using moltin R, but don't know how to enter the data below into R. Any advice?
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19 views

Stat test to use with nominal variables

I have a research question looking at whether one level of a nominal variable is more likely to elicit an action than another. We are using a control and experimental group so our IV is either ...
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14 views

What's the best stats to use for pre/post data?

I have 107 participants and had them do 2 lessons. Before lesson one, I asked 5 knowledge questions with true/false response for each. After the second lesson, I administered the same survey ...
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36 views

Which statistical significance test to use for nominal data collected from a within-subjects experiment?

I've collected some data from an experiment where I was evaluating a system. My independent variable had 4 conditions (call them C1, C2, C3 and C4). During the experiment, I asked six people to ...
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75 views

Can we combine two groups to enhance power for analysis if there are no group differences on the variables?

I am reading a peer-reviewed paper on psychology and found the author use pearson r on sex (nominal variable): The correlation table And then the authors conclude no gender difference on all ...
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197 views

Sample size for logistic regression with categorical independent variables

Trying to find a sample size for logistic regression I found a rule of thumb in http://www.medcalc.org/manual/logistic_regression.php I cite: Sample size considerations. Sample size calculation for ...
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15 views

which test for means of coded, categorical discussion forum posts?

I'm trying to wrap my head around this problem, how to state it formally for analysis (what kind of study is it) and which test(s) to run: I am comparing the content of 2 discussion forums (the study ...
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1answer
1k views

Correlation between a nominal (IV) and a continuous (DV) variable

I have a nominal variable (different topics of conversation, coded as topic0=0 etc) and a number of scale variables (DV) such as the length of a conversation. How can I derive correlations between ...
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25 views

How can mutual information be used in analysing a survey of categorical/nominal data?

I have data arising from independent surveys taken from at least 200 participants. In the survey there is a set of question of categorical and nominal types. I have no knowledge of the nature of the ...
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19 views

Variable types and level of measurement

I am trying to fit the different variables types and measurement levels into some logic, like a tree diagram, and I am not sure about some things. On one hand, you have quantitative variable vs. ...
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50 views

Excel correlate nominal and quantitative

I have the following test data: How do I correlate the "believes" with "before" to determinate if it affects the "after"? When believes is set to 1 the "after" will be (randomly) higher than when ...
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532 views

Is it possible for Cramer's V to be negative?

To my understanding, Cramer's V cannot be negative because of the way we define it. But here's what I got from SAS:
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2answers
285 views

Should types of data (nominal/ordinal/interval/ratio) really be considered types of variables?

So for instance here are the definitions that I get from standard text books Variable - characteristic of population or sample. ex. Price of a stock or grade on a test Data - actual ...
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22 views

Should IDs be nominal factors or text?

I am getting started with R. I imported by data and R decided that my ID attribute should be a factor. While technically correct, it feels misleading to me. An ID doesn't feel like a factor with ...
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58 views

Under what conditions should Likert scales be used as nominal data?

Similar to this question, Under what conditions should Likert scales be used as ordinal or interval data?, I am curious under what conditions should/could Likert scales be used as nominal data?
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20 views

Can Cramér's V tell me what to control for in my data?

For my research question, I want to find out if two different group types (IV) vary across position categories (DV) for eight different limbs. My data is nominal, so I'll be testing this by doing 8 ...
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120 views

Clustering on a data set with mixed variables

I have a data set consisting of $n$ elements with $d$ features for each element ($x_{i,f}$ means the value for the f-th feature of the i-th element). I would like to cluster this data set into $k$ ...
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2answers
91 views

Derivation of the Simpson index

I'm interested in the derivation of the Simpson diversity index. I found the normal interpretation of this index, but I'm not able to see what's the "mathematical background" of the formula. I read ...
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85 views

BUGS/JAGS for Nominal Response Model

I am a beginner with BUGS/JAGS and I was hoping to gather the opinion of you, experts. I am trying to implement a Nominal Item Response Analysis (Polytomous, not ordered, like a multiple-choice exam) ...
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1answer
33 views

How to test for a critical mass - dummy variables?

Part of my thesis is to test where the critical mass lies. Let's assume that we want to test the influence of a certain ethnic group (x) on the performance of the whole group (members of ethnic group ...
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2answers
328 views

Should I use aggregate or disaggregate data?

I have this dataset of flows: ...
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2answers
1k views

Correlation between quantitative and qualitative variables

I have a dataset composed by 5000 observations. Each observation contains the income per year of a person (from 50 to 50.000.000) and the fact of having a car (yes/no). I would like to check if a ...
2
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3answers
307 views

Linear regression on grouped data

I have a sample composed by 200.000 projects. Each project is defined according to its size ($S$) and the presence of active users ($U$). The values for $S$ are greater than zero; on the other hand, ...
2
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163 views

clustering variables of mixed types in R

I need to analyse questionnaire survey data with mixed data types (nominal, ordinal, continuous). I want to cluster the variables. So far I only have dead ends. I know I can use daisy in the ...
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3answers
371 views

How to deal with nominal variable with too many levels?

currently I'm trying to model a response variable y, and I have zip code as my independent variable, my model is logistic regression. When it comes to nominal variable, the text book method is to ...
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2answers
48 views

How do I explain correlation for my study proposal?

I am doing a study proposal for a project that looks at two different measures for evaluating the presence of a health condition, one clinical exam one diagnostic exam. the clinical exam will be ...
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71 views

Distance between nominal vectors: a review

I have a seemingly easy question which however is troubling me a bit. I have couples of vectors made up of nominal attributes. They can be of different length and sometimes some of the attributes in ...
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1answer
103 views

Non-parametric statistical test with one measurement variable and two nominal variables

I have the following data: feces density of a carnivore species subdivided according to sex. I am looking for appropriate test suggestions. I have calculated the density according to main habitat ...
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1answer
179 views

Accuracy and area under ROC curve (AUC)

If we group examples with and without class labels using clustering techniques by treating the class as an ordinary nominal attribute, the resulting clusters can then be used for classifying test ...
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1answer
201 views

Confidence Interval for ratio (response time 2 / response time 1)

We have a population of n=1000, nine binary responses (0 symptom absent, 1 present), and 2 timepoints. Note that some of the responses are heavily skewed, only 1% of the subjects are in the "symptom ...
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1answer
63 views

How to measure association of nominal values for few observations?

I have a sample with 181 observations. I measured two nominal variables for each observation and now want to calculate the association between the two variables. The problem is that one variable has ...
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1answer
495 views

Correlation among categories of categorical nominal variables

I have a data set with two categorical nominal variables (both with 5 categories). I would like to know if (and how) I am able to identify potential correlations among categories within these ...
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2answers
1k views

Correlation coefficient for non-dichotomous nominal variable and ordinal/numeric variable

I've already read all the pages in this site trying to find the answer to my problem but no one seems to be the right one form me... First I explain you the kind of data I'm working with... Let's ...
2
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2answers
61 views

Shall I treat vegetation group as an ordinal or nominal variable?

As a follow on from here: Correlation between vegetation and erosion, I am having some trouble with the type of data that I have. I am confused as to whether my four categories are ordered. ...
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117 views

Questions about nominal data

Can nominal data have uncountably many values? Are categorical data the same as nominal data? Are discrete data the same as nominal data? Thanks!
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1answer
7k views

Should Likert scale measures be treated as interval, ratio, ordinal, or nominal? [duplicate]

Forgive me, I am forgetting my basic statistics.
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216 views

Can test a hypothesis with only nominal variables?

I have a hypothesis such as "People consult internet before making a purchase decision" for a thesis research. In order to test it, I created a game where people had the option to consult "internet ...
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1answer
57 views

Need help selecting test for nominal IV with categorical DP

I am going to attempt to give you as much background as possible. My independent variable is nominal and describes the number of days after which an insect was exposed to new conditions (0,1,3,5,7). ...
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1answer
265 views

Can all methods made for certain level in measurement hierarchy used at all higher levels?

Let's say there's a measurement hierarchy for discrete variables, that looks like nominal (grade pass/fail) < ordinal (grade A/B/C) < interval (grade 90-100; 80-89; 70-79, etc). Hierarchy is ...
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1answer
82 views

Not sure whether to treat my data as nominal or scale

The data I have is based on percentages. I have several variables on percent of children that have been immunized. So one column that is one kind of immunization, and is ordered by state. So for ...