Tagged Questions

1
vote
0answers
40 views

how to analyze necessary/sufficient relationship?

Good day! I'm a second year psych grad student. From my fascination with formal logic, I wondered (just personal; not homework) about how to statistically establish necessary/sufficient ...
1
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2answers
74 views

What factors do I have to consider when deciding if creating a composite score using four t-scores is defensible psychometrically?

Edit: I've conducted an item analysis on four variables - two quizzes and two psychological attributes, namely emotional intelligence and happiness. Its a within-subject design with students as ...
2
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1answer
67 views

Ordinal reliability for small examinee population

Biswas considers "a classical-type linear model of observed score ($X$), true score ($T$), and random error ($E$)" and asserts ... in test theory, interpretation of $\rho_{TX}$ has an intuitive ...
1
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2answers
225 views

Rules of thumb for creating composite scales

Normally when I create an index I basically just take the or averages of the individual variables that comprise the index. But I'm wondering if one should / could not, take the product? E.g., a scale ...
6
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4answers
5k views

How to compute correlation between/within groups of variables?

I have a matrix of 1000 observations and 50 variables each measured on a 5-point scale. These variables are organized into groups, but there aren't an equal number of variables in each group. I'd ...
6
votes
3answers
597 views

Validating an existing questionnaire into another language

I am doing research and trying to use a questionnaire that is available in English in another language. Is there a systematic approach for validating a questionnaire in another language? What ...
5
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2answers
761 views

Item Analysis for an R newbie

I am trying to assess a 20-item multliple choice test. I want to perform an item analysis such as can be found in this example. So for each question I want the P-value and the correlation with the ...
6
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3answers
2k views

Differences between tetrachoric and Pearson correlation

Currently I'm analysing around 300 items in the field of education. I'm interested in the dimensionality of the dataset. So I compute a matrix of tetrachoric correlation. The goal is to do a factor ...