Questions tagged [validity]
An instrument is valid if it measures what it purports to measure. This is different from reliability, which means that an instrument measures (whatever it measures) in a way that is repeatable. DO NOT use this tag for `validation` model purposes.
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How do I write the R code for a correlated trait-correlated uniqueness model?
I want to perform a MTMM following the Widaman steps but the 4th model should be a correlated trait-correlated uniqueness model. I understand that the error variance of each item is correlated with ...
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7 views
Can reliability and validity assessments be considered as required constituent of the “Measurement part” in Structural Equation Modeling?
I wonder if any type of reliability and / or validity analysis can be considered as an element of the Measurement part in SEM. For example, when computing Cronbach's alpha or the AVEs of an instrument,...
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11 views
Validating censored labels
I have a database of $P$ patients' hospital encounters over a period of $T$ years. Patient $p \in \{1, 2, \ldots P\}$ visited the clinic $N_p$ times. If patient $p$ was diagnosed with condition C ($...
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9 views
Measuring Validity and reliability
Say you have an independent train ticket system where automatic refunds would be issued in case of a delayed arrival. To determine the arrival time of the train at a certain station you collect data ...
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5 views
Manipulating neuropsychology test items, controlling for changes?
If I take a subtest from an existing neuropsychological test, and take out 5 items to use independently as my methods of measurement for each level of my within-subjects factor, how can I ensure good ...
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1answer
22 views
Correlation between questionnaire to test validity
I'm doing a validation of a questionnaire for my thesis and I should investigate the validity of my test with others one. To do so I've been asked to calculate the correlation between two scales and I'...
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23 views
Questionnaire validity statistical significance
My colleagues and I, have developed a questionnaire of 116 questions, segmented in 7 constructs. Cronbach's a indices for each construct are above 70%, and it is content valid. However, when we apply ...
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18 views
Intertia significantly decreasing after running multiple k-mean clustering models
I have been spending some time running k-means clustering models using scikit-learn on a variety of feature combinations and have been using the inertia value to compare models to one another.
I've ...
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38 views
AVE and CR in JASP?
I'm new to the software JASP and need some help. Is it possible to calculate average variance extracted (AVE) and composite reliability (CR) in JASP? I need them in order to test validity and ...
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61 views
Comparing two CFA models in AMOS (only 4 items per 1-2 factors)
I am trying to test in AMOS the discriminant validity of a 3-item measure (items "1, 2 and 3" against a 1-item measure "item Z" (both are Likert scale questionnaire instruments), by comparing whether ...
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31 views
comparison between two measurement devices
I have two measurement devices accelerometer A and B. The measurement is the step time of a person walking in a corridor. A is the gold standard. I want to check the validity and reliability of B. how ...
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13 views
What do you do if participants of your study take a pretest, but not post test?
I gave pretests to several groups of participants ranging from 20 to 45 people, of which were all completed. When I gave out the post-tests, I only received back about half of the groups'. Also, ...
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19 views
Validity and Reliablity Multiple Choice Question Questionnaire
I gave questionnaires to 7-8-year-old children to answer questions about oral health knowledge. I've already collected the data but I'm still confused with validity and the reliability in SPSS.
I ...
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22 views
Survey Question Validity
I have a survey that asks the user to report their debt from their undergraduate education and their debt from their graduate education. I intend to add these two averages to measure their average ...
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23 views
Generalizability study of subscaled rating instrument
I have a school rating ($1$ thru $4$) instrument that consists of $9$ subscales (e.g., classroom instruction, school management etc.). Under each subscale, I have $6$ items on which rating occurs.
I ...
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17 views
Cronbachs alpha interpretation - what does var.r and med.r mean?
i have used the psych::alpha to find the cronbachs alpha values, but i cannot find any interpretation for some parts of the output, namely:
...
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1answer
23 views
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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1answer
54 views
Do I estimate factor loadings in a confirmatory factor anlysis (CFA) aimed at verifying an exploratory factor analysis (EFA)?
I decided to use a questionnaire published by another researcher (paper and supplementary here).
In the article they perform an EFA, find two factors, and report the resulting factor loadings (...
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32 views
How to test nomological validity with lavaan?
in my understanding, I need to test nomological validity with SEM. But what exactly should I look at in e.g. summary(fit1, standardized=TRUE, fit.measures=TRUE)?
Code for reference:
...
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1answer
34 views
Validity of ARDL regression when there is I(2) variable
I am trying to model relationship between Y(t) and Y(t-1), X(t), X(t-1) and Z(t) using ARDL model. Most cases these time-series are I(0) or I(1). However sometimes I encounter I(2) or higher order.
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1answer
793 views
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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122 views
Wilcoxon signed-rank test for paired and repeated measures data
I have a dataset with 45 participants, each with 1-7 datapoints/observations (126 total observations). Each of these observations represents a window of time in which two different methods attempt to ...
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56 views
How can statistics be used to avoid “Lending False Credibility To Decisions We've Already Made”
In light of this article Data Science Has Become About Lending False Credibility To Decisions We've Already Made published in Forbes, I would appreciate input from the statistical and data science ...
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15 views
Are there any studies of generalized error performance that don't assume data quality is constant with sample size?
As far as I know, much of the statistical and machine learning literature where modeling algorithms are compared for their generalization error performance as a function of sample size (think of ...
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12 views
factorial designed study within between
IV1 : alcohol use, IV2: breathing exercise (both of them within subject variable) IV3: gender (between subject variable). My research question is that: ''Does alcohol usage and breathing exercise's ...
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1answer
95 views
Calculating Confidence Interval with log-transformation
I fitted a linear regression with a 3rd order interaction and adjustment for confounding variable which looks like this:
$$
log(Y) = Ī²_1S + Ī²_2T + Ī²_3M + Ī²_4ST + Ī²_5SM + Ī²_6TM + Ī²_7STM + Ī²_XX
$$
...
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1answer
17 views
Can findings based on low values be considered valid?
Lets say i do have a TimeSeries with N > 300 but values like [0, 1, 2, 1, 2, 0, 2, ...] representing the visitors count of a website per day.
Since there are only few visitors and each of them can be ...
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1answer
107 views
What does “the hypotheses … are verified as null” mean?
Context:
This article examines the criterion-related validity of the results obtained by the application of four different methods of assessment to the correction of a second-year exam of
...
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2answers
179 views
Reweighting features in PAM/K-means clustering
As stated in Hennig et al. 2016 Handbook of cluster analysis:
If for subject matter reasons some variables are more important than
others regardless of the within-variable variation, one could ...
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3answers
868 views
Does a statistic used as a measure becomes invalid after it's reported on? [closed]
Apologies if this the wrong place to ask. but i'm trying to explain to a director that his Statistics don't show the truth because he is demanding that the stats are what is reported on and staff are ...
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1answer
73 views
How to assess predictive validity of a variable on the outcome?
I am looking to assess the predictive validity of two measures (M1 and M2) on a binary outcome. After constructing my model, do I just calculate odds ratios and compare the odds ratios for the two ...
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18 views
Assessment of Statistical Validity
I have results from a questionnaire I have created from 32 participants. The questionnaire assesses 3 domains. I have been able to assess reliability with Cronbach's alpha but I am unsure how to ...
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38 views
Measuring emotion differentiation on a within-person level.
To measure emotion differentiation, which refers to the precision of an individual to accurately describe and distinguish between different emotional states, many studies have used a between-person ...
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1answer
104 views
Does changing the point range of items of a construct measured through likert scale affect in any way validity and reliability of the construct?
I am using a pre-existing universal tested scale to measure a specific construct. The construct is measured through 5 items on a 5 points likert scale. However, I would probably need to change the ...
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1answer
64 views
If the Pearson correlation coefficient is small/weak, can it have criterion validity?
The r value I have obtained is -0.190 and p = 0.410.
As scores on stress increase, scores on eating habits decrease.
I know from my textbook that criterion validity is about whether your measure is ...
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1answer
32 views
Validate 10% sample from population
I have two databases which include amount of passengers between two routes.
One is the full dataset, while the other is supposedly a 10% sample.
So for example, the full database will display a route ...
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1answer
79 views
Teaching examples for internal validity: published experiments later shown to be confounded in an interesting way
There are some good examples of interesting/fun spurious correlations here (Examples for teaching: Correlation does not mean causation). Many/most of these are "funny" examples that aren't likely to ...
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2answers
430 views
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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28 views
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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1answer
31 views
Validity / reliability of instrument used by 2 people at 2 sites
How can the validity/reliability of a semi-structured interview tool be determined, conducted by two persons at two different sites separately? For instance, one person is using the tool with male ...
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1answer
98 views
Survival analysis: Excluding cases of trivial follow-up time?
I am finishing up the data collection for my retrospective cohort study, which I have designed with the intention of conducting survival analysis. Our outcomes of interest are recurrence, metastasis, ...
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58 views
Cronbach alpha application
I developed a questionnaire to measure some factors influence in decision using related literature and after some interviews. Now I have to validate and see how to distribute among the target group. I ...
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1answer
583 views
Should I calculate Cronbach's alpha for a linear regression model?
I'm interested in modelling a trait Y using variables X1, X2, X3.
I'm using a linear regression model to predict trait Y using the independent variables and therefore want to avoid multicollinearity ...
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1answer
189 views
quantitative relation between standard error of measurement and validity
Is there a function to estimate the gain in predictive validity with the decrease of the standard error of measurement?
E.g. If the short version of a test has predictive validity of 0.35 and ...
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1answer
472 views
How is independent T-Test valid for unequal samples?
I have two groups that I wish to assess for statistically significant differences (n1=1520 / n2=115). I'm actually using T-Test for independent samples.
As far as I know, there isn't a problem here ...
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2answers
438 views
How can I determine the accuracy of correlation?
When I performed correlation analysis of C02 emission with around four-hundred attributes, i found out that C02 emission and cereal production has a correlation value of 0.98 where as the most obvious ...
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3answers
348 views
Validity of using a combination of Wilcoxon tests and Spearman rho as an alternative to GLM?
I recently read a paper where the authors used either (a) a generalised linear model or (b) a combination of Wilcoxon rank sum tests and Spearmanās rank correlation, depending on whether the data ...
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Validity of conclusion of statistical tests when comparing two groups of observations in an experiment
I am just reading the results of an experiment, and I am having a hard time estimating their validity.
In the experiment, several participant had to perform a certain task twice, once with the ...
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1answer
694 views
Chi-square Discriminant Validity Test with Lavaan (R)?
I have a four factor scale that I just finished CFA on, and I was advised to use the chi-square test of differences to check for discriminant validity to reinforce my AVE based test for it. I read ...
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33 views
Does reliability/validity apply on manually summed items?
For a subscale of mine, it showed a reliability in the 0.6 range which is in the 'questionable' range and it showed an AVE (convergent validity) of just 0.3. Now I know that it will be perceived as a ...
