Questions tagged [cronbachs-alpha]

Cronbach's $\alpha$ is an estimate of the reliability (specifically, of one its aspect called internal consistency or item-item homogeneity) of a unidimensional test, a construct. It is used mostly in psychometrics and occasionally in other disciplines.

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Are Cronbach's alpha of the subscale the same as in correlated-factor model and bifactor model?

I have an instrument that holds a correlated-factor model and a bifactor model (one general model and four orthogonal factors). I need to report the reliability of each subscale. I've computed Omega (...
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Explaining Variance in Regression Model of highly correlated data

I am currently tracking an Index fund of stock and it's underlying Alpha Factors(Liquidation, Volume, Investor Sentiment etc). I have the historical data of these Alpha Factors, as well as the Index's ...
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What I supposed to do if Cronbach's alpha is negative? [closed]

I have 100 sample with 8 questions with answers between Yes or No (Guttman scale). Cronbach's alpha is badly negative. I have checked everything I could think of, but the result did not change. I have ...
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How to calculate power?

I was wondering how you calculated the power via Gpower with these results? There are a total of 87 participants and the alpha level is 0.05. It is a longitudinal design in which I performed a ...
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High Cronbach's alpha

I am doing a pilot study of 30 samples. I am getting Cronbach Alpha of 0.933 to 0.991. I tried deleting few items and running the analysis. But still Cronbach Alpha has changed much. My specific ...
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Justify the deletion of a factor in EFA

I have done an EFA on 180 observations. In order to explain my latent variables I have considered 24 variables and I get 7 factors. Unfortunately 2 factors among the 7 have a cronbach's alpha around 0....
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Calculating Cronbach's Alpha for New Study Sample

I have been asked to calculate Cronbach's alpha for the instruments used in a completed study which utilized multiple questionnaires composed of Likert-type questions. These questionnaires are already ...
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Tests for item rating reliability (Cronbach's alpha?)

Here is the situation: I am asking participants to provide some names of a certain category. (Imagine a verbal fluency task where you are asked to name as many animals as you can in the space of 1 ...
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Cronbach Alpha help

I had a test that I use to evaluate participants in a quality monitoring - I want to check the reliability of the tool. I got the average of each category, can I use Cronbach alpha to check ...
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KMO and Cronbach's Alpha in a multiple regression

I am trying to figure out a reviewer's comments on a manuscript I have submitted. In the paper I fit multiple linear regressions using OLS. The cross-sectional observations are countries. My dependent ...
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What is the ideal measure of reliability when each subject only responds to a subset of items?

Lets say I have a measure with 40 items, but each subject only responded to 20 of them. Is there a way to still calculate reliability in R? I've looked into Robust Cronbach's Alpha using the "...
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How to identify careless responders when items negatively correlate with the total scale

I'm calculating the Cronbach's alpha on a dataset with the scores of the Coping Orientations to the Problems Experienced (COPE-NVI-25) with R and the psych package. ...
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Calculating inter-rater reliability with 1 primary rater and a couple other secondary raters

I'm trying to figure out what to use to calculate inter-rater reliability for a set of behavioral coding. There's one individual codes the whole set (primary coder; e.g. codes data ID 1-300) and a few ...
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Metafor Package: How to conduct Meta Regression with reliability generalization

How to conduct meta regression in "metafor" after I got I2 heterogenity 94%. My study reliability generalization alpha Cronbach, with continuous and categorical moderator variable. Thanks ...
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Denotion of Cronbach's Alpha based on Polychorric Correlations

we assessed several 5 point Likert-Scale items in a questionnaire and are interested in Cronbach's $\alpha$ for the internal consistency. I recently read (here) that it can be more precise to used ...
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Correlation between subscales

I have used a scale, which includes 3 subscales. Given that the 3 subscales make part of the same,validated instrument, what conclusions can be drawn from the fact that a pair of subscales ...
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Inter-rater reliability using two raters on the same subjects

I'm very new to R, so I'm sorry if this is a really basic question. I'm trying to calculate interrater reliability using Cronbach's alpha for two raters using the same assessment on the same six ...
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Is there any way to visualize Cronbach's alpha value and test-retest reliability (intraclass correlation coefficient) analysis outcomes?

Is there any way to visualize Cronbach's alpha value and test-retest reliability (intraclass correlation coefficient) analysis outcome? I use Rstudio as my daily driver, so if there's any way to ...
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The correction for attenuation

The reliability of the task that I measured is very low for some sub-tasks. So, I tried to correct the correlation coefficient with Spearman's disattenuation formula: $r_{x'y'} = r_{xy}/\sqrt(r_{xx}r_{...
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Cronbachs alpha for items with different scales

I have a sample size of N=63 and 6 items measuring risk tolerance. Now, I want to calculate Cronbachs alpha, however, the 6 items have different scales. For example, the first item has a scale from 1-...
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When running a reliability analysis (using Cronbach's alpha) in SPSS, what does "scale" refer to? Do I have to compute a scale explicitly beforehand?

Is the scale meant to represent the sum of responses (each response is an element of, say, the set {1, 2, 3, 4, 5}) of a case (an individual) to a set of questions (items)? And is a "scale mean&...
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IRT: What is enough information? And can a test provide too much?

I was wondering what makes for a good test information value in IRT, and came across this: Reliability: Item and test information functions graphically reflect how reliably the individual items and ...
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How to use Cronbach's Alpha?

Is it appropriate to use Cronbach's Alpha for nominal variables? I have 20 nominal variables (two dimensions with 10 questions each) that ask about the characteristics of work performance. The ...
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Fleiss' Kappa v. Cohen's Kappa v. Cronbach's Alpha

I am working on a project that compares two methods of assessing whether certain topics come up in a therapy session. I am comparing a checklist full of dichotomous (y/n) items completed by an ...
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Alternative to Cronbach's alpha if $n$ is too small for McDonald's omega?

I have a very high Cronbach's Alpha of $0.966$ (and composite reliability of $0.969$). My questionnaire has a 1-factor-structure, which makes it compatible with Cronbach's Alpha, but it has 22 items. ...
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Cronbach's alpha and reverse-scored items

When calculating Cronbach's $\alpha$, would I include the reverse scores? I have 20 items in total, including 11 reverse-scored items. Would I just calculate the original scores?
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Cronbach's Alpha with repeated missing values

I would like to use Cronbach's Alpha to check the fiability or internal consistency of a cognitive task. The task has a certain number of trials which were coded with zeros (incorrect trial) and ones (...
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Adjust alpha when switching from one-tailed t-test to two-tailed

I started with a hypothesis that says e.g. A is larger than B which would usually call for a one-tailed t-test. But after acquiring the data it turns out that the effect seems to be contrary to my ...
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Should reliability test (cronbach alpha) include missing values?

I am currently doing a reliability test for my questionnaires with 34 respondents. However, there are some missing values in the questionnaires which I'm not sure whether I need to include or exclude ...
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Is it always needed to do a validity test for variables?

Let's say I have one variable called "perceived image", which is measured with 6 items (questions) that I adapted from previous literature. If I have a Cronbach's alpha > 0.7 (for reliability), do I ...
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Unidimensionality in IRT

I recently came across the definition of unidimensionality (in the context of IRT and internal consistency reliability, specifically Cronbach's alpha). Johnsosn (2007) states that There is a one-...
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item-total correlation vs. inter-item correlation

I am assesing the reliability and validity of an 16-item multuiple choice test supposed to test language skills. Cronbach's apha is "questionable" with .65. I am having troubles interpreting the ...
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Low internal consistency

I am currently analysing the data for a survey I have completed. In doing so, one question is quite simple (nominal) and require a typical “I do/I do not” and “I do not/I do” response from the ...
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Is it correct to a total Cronbach´s alpha analysis to a tridimensional scale?

There´s a statement that says that Cronbach´s alpha assumes unidimensionality. In that sense, is it correct to calculate a global alpha? I mean, by including all 3 dimensions, and not by separating ...
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What is the difference between Cronbach's alpha and standardized Cronbach's alpha?

I found in the wiki article a definition of a standardized Cronbach's alpha but nothing is said what it is and about its relation to the original Cronbach's alpha: I found at What is Cronbach's ...
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How do you calculate a new scale from two given variables and then find out the cronbach-alpha?

The question concerns two variables with scores from a personality test, Ptest1 and Ptest2 with values from 60 participants from each variable. So how I can convert these two variables into a new ...
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Cronbach alpha with knowledge items?

I have a very specific question about the application of Cronbach's alpha to data with trichotomous responses (true-false-don't know). I have an acquaintance I'm helping replicate a study using a 45 ...
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Cronbach alpha and item selection

I am a relative novice when it comes to statistical analysis, so forgive me if my question is unclear, or simply stupid. I am also not a matemathician, as I work in social science research, but I have ...
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Interpreting low Cronbach's alpha value in CATPCA

I ran categorical principal component analysis (CATPCA) on the data that I collected through a questionnaire. The purpose of the questionnaire was to understand pedestrians intentions and attitudes ...
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What is the point of reporting split-half reliability together with Cronbach's alpha?

In several journal articles I read, autors report split-half reliability (Guttman formula obtained if questionnaire is splited into two parts: odd items and even items, usually) together with Cronbach'...
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Cronbach's alpha: how many digits to report?

I submitted my first paper to a peer-reviewed journal and got lots of feedback, questions and criticism back. One point was related to the number of digits I report for estimated values (e.g. for ...
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What is the relation between Cronbach's alpha and pair-wise correlation?

I generate multiple responses using a multivariate normal distribution with means of 5 and standard deviation of 2; I want ten responses and set the correlation between responses to be 0.5. ...
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Why does a factor need to be internally consistent?

I'm wondering exactly what the question says: Why does a factor (as linear combination of its items) need to be internally consistent? If I want to use a factor found in a factor analysis as a ...
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Psychometric properties on new sample with old questionnaire

When using a decades old inventory, questionnaire or factor from a questionnaire, is it important to retest the psychometric properties of this with the current sample, i.e. compute new Cronbach's ...
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Correlation between Likert scale independent variables and multiple categorical dependent variables

Based on the above diagram: My alpha for the independent variable is above 0.7 My Alpha is negative for the dependent variable. (I tried reversing items with negative words and the option of if ...
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Cronbach's alpha -- optimum value is 1.00?

I have been brushing up on some stats and figure I'd have a look at Cronbach's alpha. As I understand it, a higher alpha coefficient means a greater interrelation between all the items. If items are ...
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How to combine different type of items of a questionnaire into a variable

I'm doing a research where I applied a questionnaire with 67 items measuring 5 variables. The issue is some questions are in Likert scale (0 to 10 and 1 to 5), some Yes, No, some open questions, ...
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Varying Likert Scale Categories

I hope that someone can help me with this question. I created a questionnaire that has different scales for each of the questions under one construct. Each of the questions still have a 5 point ...
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Are reliability and validity measures necessary for all parts of a survey

I am conducting analysis on a questionnaire which was a three-part study, not three separate studies. I asked the same exact set of validated scale questions for specific constructs for three ...
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do cronbach and factor analysis work together

I am writing a Master's Thesis based on a four construct model. I know I have to conduct a Cronbach's alpha test for reliability and I also need to conduct a confirmatory factor analysis for validity ...
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