Questions tagged [scales]
Scales used to express measurements. Usually ratio, interval, ordinal or nominal types of scales are recognized. Dichotomous and count types are sometimes seen as their own. Other classifications exist. [For "scale" as a sum of individual items in psychometry - see also tag 'psychometrics'.]
416 questions
2 votes
2 answers
90 views
3 point likert scale?
i am working on my master thesis and struggle a bit with creating a variable. I am going to perform linear regression. Maybe a stupid question, but for one of my main independent variables I want to ...
- 21
3 votes
1 answer
81 views
Compare Hb values measured by two different hemoglobin meters
I have two sets of hemoglobin measurements from two different machines, each measuring different individuals. I don't have calibration information, but I do know the minimum and maximum values for ...
- 635
4 votes
0 answers
107 views
Transform and analyze bipolar / bidirectional ordinal scale to use as primary outcome in a clinical trial?
We are running an observational clinical study on sedation during painful procedures and planning a future randomized trial. The primary outcome variable is a 6-level ordinal scale characterizing ...
- 163
3 votes
1 answer
117 views
Ordinal item should be regressed as such using ordered regression. But how can ordinal scales be treated using ordered regression?
Many fields use questionnaires that ask questions with ordered answer options. For instance, a question might be I have a good self-esteem, with response options ranging from Fully disagree; Disagree; ...
- 160
0 votes
0 answers
28 views
Why does centering and scaling change my model (binomial response glmm) coefficients' p-values, but just scaling doesn't? [duplicate]
I have a glmm in R with 4 fixed effects, 4 interaction effects, 2 random effects, and a binomial response variable. I have two versions of this model, both with the same model strucure: ...
2 votes
1 answer
177 views
Factor Analysis: Theoretically Five Factors Expected, but Only One Emerges – What Should I Do?
I am currently conducting a factor analysis on a scale that theoretically consists of five factors. However, both Principal Component Analysis (PCA) and Maximum Likelihood (ML) extraction methods in ...
1 vote
1 answer
147 views
Is $100\times\frac{X_i}{X_{\text{max}}}$, a known formula for scaling data?
I have data on the depth of soil below the surface, and the depth values are in increasing order with irregular spacing. Note that, the first depth does not start at $0$, but at a number like $0.245$ ...
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0 votes
0 answers
26 views
What kind of algebraic structure is a ratio scale? [duplicate]
In a seminal paper, Stevens (1946) introduced a fourfold classification of scales: nominal, ordinal, interval, and ratio. He based this classification on the types of comparisons the scale preserves ...
- 689
2 votes
0 answers
126 views
How to scale circular variables [closed]
I routinely scale non-circular variables using methods you can see here. If I use the same methods with circular data, the cutoff creates issues, such as huge "jumps" in the data depending ...
1 vote
1 answer
83 views
Plotting scaled model predictors
You may want to scale a continuous variable before you use it as a model predictor. For example, using the mtcars dataset you can model mpg as a response to scaled ...
4 votes
1 answer
204 views
Logic of scales of measurement (Nominal, ordinal, etc.) when transforming variables
Scales of measurement often discussed as: Nominal: Qualitative category with no order Ordinal: Order but no meaningful distance between values Interval: Order and meaningful distance between values ...
- 1,106
3 votes
1 answer
295 views
Are dichotomous categorical variables technically interval/continuous measures?
In my university statistics book it says "Dichotomous categorical variables are easily handled in MRA. This is because they are by definition, an interval (continuous) measure.". However I ...
- 57
1 vote
2 answers
869 views
Likert scale and sample size
I want to study the satisfaction of a mother receiving paper or website information. I will have at least 5 questions, with Likert scale (5 points) each time. For the sample size: Should I calculate ...
- 11
2 votes
0 answers
152 views
What test of reliability for repeated measurements of the same scale?
I need to ask you for help on what method to use to calculate the reliability and validity of a scale that I measured repeatedly on the same subjects during an experiment. Let me explain: normally ...
- 101
5 votes
3 answers
2k views
How do I compare the results between two different Likert Scales questionnaires?
For my dissertation, I am currently evaluating pharmacy students' perception on two distinct academic electronic health record systems - A and B. The students were asked to identify how much they ...
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