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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Choosing between two scales

I am investigating a scale of consumer ethnocentrism - CETSCALE. I do not have much knowledge in econometrics, scales, etc., however: a) research papers report that the standard 17-item scale is ...
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Statistical significance of cluster validity

Hi I m working on a unsupervised problem to partition my dataset. I have access to the class labels for this dataset. Now I am trying to use Jaccard coefficient to compute correlation between cluster ...
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Validity of PCA obtained results

If I have built a certain construct measuring scale aggregating items from different previously validated scales, I am unsure what strategy would be best to validate my resulting scale. I intend to ...
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Calculate Cronbach's alpha over test set or over test time?

Reviewers have requested me to calculate Cronbach's alpha for tests I administered during an experiment. There are two ways I can do it (at least), and I'm wondering which is more appropriate. ...
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Validating a manual classification

I am classifying some political articles by their bias w.r.t. a particular issue into 5 categories (strongly in favour, mildly in favour, neutral, mildly against, strongly against). For most cases, ...
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Validity of running 2 conditional logistic regression tests on a data set

My current research is about hibernation site selection in box turtles. In order to determine selection, I collected a range of variables about the soil that the turtle hibernated in as well as the ...
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47 views

households survey data - determine 'valid' product categories

I'm working with household survey data where households report their expenditure for various products. The goal is to look into income elasticities for various products thus in essence I'm interested ...
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54 views

Covariance between factors in CFA (Amos)

I ran a Confirmatory Factor Analysis (CFA) in Amos and obtained a model with high covariance between the factors. James described this covariance in his video as alarming. What can I do to tackle ...
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66 views

Evaluation measures of overlapping clustering

I have a dataset of Facebook users and a set of different clustering algorithms. The project goal is to draw up a rank between these algorithms in order to understand which of them are the good ones. ...
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Validity of a statistical procedure to calculate an odds ratio for a Fisher's exact test?

I am trying to determine whether this is a valid statistical procedure. I have ~1000 samples, and each sample has around 1-500 data points. Each data point consists of two fractions (value1 and ...
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26 views

Selection Bias with Groups

I have conducted a pre-post test study with a set of 20 participants. There were two independent variables and therefore 4 groups of 5 participants each. The experiment took place in a classroom and ...
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239 views

Identification of useless questions from a questionnaire

I'm developing a questionnaire. To improve its reliability and validity I want to use statistical methods. I want to eliminate questions whose answers are always the same. This means that nearly all ...
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If a measure is valid (but not necesarily reliable), can it be consistently replicated?

I had this question on an exam, and I was positive that the answer was A. The Beck Depression Inventory is a scale intended to measure depression levels, with higher scores indicative of higher ...
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Assessing questionnaire reliability using test-retest measures

I am an undergraduate student with not much knowledge regarding statistics. I was hoping you would be able to help me by answering a question. I am currently checking the reliability and validity of ...
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Small data set and validity of Multilevel Regression results

I want to estimate a hierarchical multilevel regression (two levels). My data set is fairly small: 25 groups and 255 individual observations distributed unequally among groups (group member size ...
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Do reliability and construct validity have same technical(statistical) assumptions?

It appears that reliability and construct validity have a similar backing in terms of statistics. Is it true ?
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209 views

CFA Fit Measure Thresholds for New Scales

A well established questionnaire measuring interpersonal relations is modified to measure interorganizational relations. 11 parameters of the relation are determined by 4 items each. Items are removed ...
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76 views

Can we use CFA (confirmatory factor analysis) to ascertain validity coefficient?

Validity coefficient is an important measure for test development especially in psychology and sociology wherein we have too indirect measurements. Perhaps we have different ways to know its size.
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How does reliability and validity affect the results (descriptive statistics)?

Okay, I think this might be a stupid question but I just can't quite seem to get there. I understand what reliability and validity is, but I don't understand just what I should do with it when looking ...
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318 views

Validity Index Pseudo F for K-Means Clustering

The Validity Index "Pseudo F" is described as: (between-cluster-sum-of-squares / (c-1)) / (within-cluster-sum-of-squares / (n-c)) with c beeing the number of clusters and n beeing the number of ...
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Is this a valid test?

I have 5000 cases vs 5000 controls with positive/negative outcome. chi.test shows no significance for this data. I get significance when subsetting cases on VarX, ...
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Doing CFA on a known theoretical model, but having problems with convergent and discriminant validity

I did a survey based on the UTAUT model / theory with standard questions used. The N was 150. I am trying to validate the model for my survey with structural equation modeling (via the AMOS software). ...
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how to compare partial ratings of a set of data by different groups of participants?

So lets say I have N items and I want to rate their relevance (say on a 5-point likert scale: 1 being least and 5 being most relevant) to the "perception of beauty" and I have M number of ...
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What is validity of an inference procedure?

What is validity of an inference procedure? The inference procedure can be point estimator, confidence interval, or a testing rule. I saw "validity" in Diggle et al's Longitudinal Data Analysis: ...
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How can reliability and validity of content analysis be quantified when there is only one person coding the data?

How can reliability and validity of content analysis be quantified when there is only one person coding the data?
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Hand hygiene observations

How much validity is there in doing external hand hygiene observations in a hospital where another facility observes for a total of 6 hrs. twice a year and reports that data out, when the observed ...
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233 views

Using existing questionnaire

I will be doing my colloquium and will be using existing questionnaires. I would like to know if there are authors/authorities who say that an existing questionnaire need not be validated. The ...
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How to calculate validity of questionnaire in SPSS?

I have 3 types of questionnaires, A 15 item scale with each item on a 7-point Likert type scale. Six subscales each containing different number of items 21 subscales each containing 4 items. ...
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How to test relative validity statistically?

I am trying to understand a) what relative validity is, and b) how to test it statistically. So far I have gathered, from sources such as this that relative validity is a larger reliability in ...
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183 views

Under what circumstances is an N < 30 acceptable?

I am doing some research in which I want to expose subjects to an "unusual" event and record their response. I am recording the subjects' responses via a sensitive brain instrument, so I've been told ...
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How to validate a survey when using Likert scale?

I have developed a very simple survey to measure the attitudes of students toward science fairs. It makes use of the Likert Scale and Open Ended Questions. Do you have a recommendation for the type ...
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How to reduce number of items using factor analysis, internal consistency, and item response theory in conjunction?

I am in the process of empirically developing a questionnaire and I will be using arbitrary numbers in this example to illustrate. For context, I am developing a psychological questionnaire aimed at ...
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validity coefficient & $\rho$

Is the validity coefficient the same thing as $\rho$, where $\rho = \frac{COV_{XY}}{SD_X SD_Y}$?
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383 views

Looking for a good online resource about survey design and analysis

What is a good and relatively brief overview of good practice for getting valid results from surveys. I'm particularly interested in something about good survey design and analysis.
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Can I delete excessive number of multivariate outliers, like over 10% in sample?

I have a dataset with around 9000 cases, I'm running a factor analysis and I have found that 1100 cases are identified as being a multivariate outlier. Is it alright for me to got ahead and delete ...
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427 views

Reliability and validity of a standard survey

I had eleven people play five versions of a video game in single sessions, for a total of 55 sessions (11x5). I used the Task Evaluation Questionnaire from the Intrinsic Motivation Inventory to ...
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References for creating neuropsychological composite scores

I am a doctoral student in clinical neuropsychology, and am in the process of creating z-unit weighted composite scores based on a battery of ability tests (i.e., attention/executive functions ...
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How to NOT use statistics

This is sort of an open ended question but I wanna be clear. Given a sufficient population you might be able to learn something (this is the open part) but whatever you learn about your population, ...