Psychometrics has evolved as a subfield of psychology to become the science of measurement of unobservable individual characteristics.

learn more… | top users | synonyms

0
votes
0answers
36 views

Is the use of PCA appropriate to validate a designed questionnaire?

I looked at the questions that may already have my answer but unfortunately it is not the case. I would like to ask again my question which has been revised to fit the rules. I am to measure 5 ...
0
votes
0answers
11 views

test analysis and test difficulty/ discrimination [closed]

1.discuss the purpose of test analysis. 2.discuss the importance of difficulty or discrimination in the development of test items. i do not understand the the importance of these in test development ...
0
votes
0answers
13 views

The differences between criterion validity and operational validity

In some psychological articles, I have seen the term "operational validity". It is often used instead of "criterion validity". What are the differences between these two concepts?
0
votes
0answers
19 views

Attitude measurement – Score classification – Why using percentiles?

Once we have raw scores from a group of Likert scale items, why are percentiles used instead of considering all the possible scores from the total number items when classifying results of individuals ...
1
vote
0answers
21 views

A measure of creativity from mind maps [migrated]

I have an experiment with 500 students who where asked to solve a general problem. Each student had the assignment to find as many solutions as possible to the problem in 15 minutes. Solutions where ...
1
vote
0answers
17 views

Combining different raters scores

In my experiment two raters evaluate 100 products, both expressing an "innovation score" on a likert scale (range is 1 to 5, where 1 is "not innovative" and 5 is "disruptive innovation"). I ...
1
vote
0answers
11 views

Which CFA model is the best fit in my translation & validation study?

I have translated and adapted a questionnaire (based on a 5 factor model; 23 items) into my native language by following ITC and MAPI guidelines. Forward / backward translation, expert panel review, ...
1
vote
1answer
27 views

Questions regarding interpretation of item parameters: inconsistent results between classical item analysis and item response analysis

I was not trained as a psychometrician, so my questions may be concept-related. If you know different resources, books, or articles that can clear my confusions, please let me know. Thank you very ...
1
vote
1answer
20 views

Where I can find resources to learn how to calculate the sample size representativeness, and realiability and validity of questionnaires?

I'm totally newbie in psychometrics but starting from a research paper with full data I would like to understand: how to calculate if the sample size is representative; how to calculate reliability ...
3
votes
1answer
40 views

Is it possible to do IRT distractor analysis using R?

I've been using the mirt package to analyse a few response matrixes I have through IRT. However, every time I need to perform distractor analysis, I end up having ...
4
votes
1answer
85 views

Questions Regarding Item Response Models – the 3PL model vs. the mixture of 2PL and 3PL model

I currently work on an item analysis for an assessment. The assessment consists of 25 multiple-choice questions. Each question has 4 choices with one correct answer. I used different IRT models to ...
1
vote
0answers
12 views

Correction of data using a correlation

Suppose I have measured the outcome variable A using a (psychophysical) test that determines the ability of a subject to discriminate between two stimuli with a certain difference (the variable X). It ...
2
votes
1answer
61 views

Item discrimination of poorly targeted items

In test theory, it appears to be widely recognized that very "easy" or "very difficult" items, relative to the ability of the sample of respondents, will have deflated correlations with the rest of ...
1
vote
1answer
25 views

An invalid questionnare with valid resultant scores?

In what situation, a questionnaire could be invalid but its resultant scores could be valid? I received a comment from a journal article reviewer that says: In keeping with the preferred ...
1
vote
0answers
11 views

Is there any research that compares Likert scale questions to “satisfaction” scale questions?

I'm trying to put together a questionnaire for measuring employee satisfaction with an internal process. I'd like to figure out if there is reason to prefer: ...
0
votes
0answers
20 views

Is a representative sample necessary to assess construct validity?

To generalize results to a greater population, a representative sample is necessary. In developing a psychometrically valid instrument, via confirmatory factor analysis or item response theory, we are ...
6
votes
2answers
138 views

What is a good method to identify outliers in exam data?

I give my students an exam that has 8 questions on it. Each question is about a particular topic. The exam is made up on the fly by randomly selecting 1 question for each topic from a pool of ...
0
votes
0answers
33 views

How to build a perceptual scale using ratio measurements?

I have several physical samples of a material that vary according to some physical measure, e.g. hardness, roughness, brightness etc. Let's use brightness as the example. Now, I am not so much ...
3
votes
0answers
63 views

How high is too high with Cronbach's alpha?

Someone in my organization just sent me a scale they developed (modified items from five separate scales used in published research) to measure an employee's readiness for change. They tested the ...
0
votes
1answer
77 views

What is the statistic to calculate Cronbach's alpha for Polytomous items in R

Does anyone know, what is the function which can calculate Cronbach's alpha for polytomous items with different categories in R? Thank you
1
vote
1answer
28 views

Reading recommendations for psychometric refinement

a research project turned up a large number of survey instruments on a specific topic. There is a great deal of conceptual item overlap in these instruments, but they do differ in some key ways, ...
1
vote
0answers
28 views

Confidence interval for psychometric binomial GLM model on more than one subject in R

I'm trying to estimate the confidence interval of a psychometric curve (binomial probit GLM), for a population (now only two subjects). Suppose I've subject "a" and subject "b", which performs ...
-1
votes
1answer
63 views

Sum of percentile rank scores of two or more variables

I need to sum some variables that are on different scales to make a new one. I'm wondering If it's correct to calculate the percentile scores first, and then to sum them up. Imagine I have to ...
1
vote
0answers
25 views

Item Information Distorting Scale

I'm refining a psychometric questionnaire and working to estimate (2PL) IRT parameters for the items in order to score the items. It's a small scale consisting of 5 questions. The MAP and VSS-1 ...
7
votes
2answers
142 views

A person repeatedly selects the two most similar items out of three. How to model/estimate a perceptual distance between the items?

A person is given three items, say pictures of faces, and is asked to pick out which two of the three faces are the most similar. This is repeated a large number of times with different combinations ...
4
votes
0answers
82 views

How to quickly identify participants responding randomly to self-report psychometric tests with many items?

Many psychological studies involve getting participants to answer a hundred or more closed ended questions. A standard context would be a personality test with 100 items where each item is answered on ...
2
votes
1answer
36 views

Publications in the social sciences or psychology based on freely available datasets?

There are a lot of datasets freely available across the web (see CV questions here, here, or here). Yet, I want the reverse: I am looking for a list of publications in the social sciences or ...
1
vote
0answers
24 views

Factor analysis without theoretical congruence

I've been working with certain personality theory, which I'm trying to measure in a sample of students. It's a foreign theory, so I created an instrument for my specific population. I got a Cronbach's ...
0
votes
0answers
40 views

Identifying the number of conditions by which variance components will be divided in Generalizability Theory using QME R package

I'm using QME R Package (can be downloaded from here) to calculate Generalizability ...
1
vote
0answers
33 views

Measure difference in answers on survey depending on item response options

For my thesis I sent out a questionnaire that has 10 questions. I set defaults: the first seven question had the default set to the desired answer and the last three questions had the default set to ...
2
votes
0answers
19 views

Estimating and using reliability metric with the same data

I'd like to know if it is reasonable to use the same set of data to estimate and use a reliability metric from repeated measures? I am mostly interesting by the minimal detectable change (MDC). But I ...
2
votes
0answers
44 views

Threshold for psychometric experiment with three (or more) possible choices

I'm running an experiment where subjects are viewing a stimulus, and they have to decide if the stimulus is brighter/darker/identical in respect to a standard image. Stimulus luminosity actually ...
0
votes
0answers
67 views

Estimates of regression coefficients at subject- vs group-level

For each of several subjects, I have mean reaction times for each of several stimuli. For each individual subject, I want to regress the RTs (as Y) against the stimuli (as X) and see if I get a slope ...
2
votes
0answers
50 views

How to deal with floor effect

I am in the process of validating a five-items scale for measuring dependence on substance 'X'. I have collected data from 98 people who used the substance under consideration at least once weekly for ...
1
vote
1answer
52 views

Correlations within Factor in a psychometric measurement instrument

I am working with results of a psychometric test. There are twelve factors and each have three subfactors. My problem is that one of the subfactors correlates very highly 0.3 to 0.7 with subfactors of ...
0
votes
0answers
39 views

Testing face validity of a questionnaire

I would like to validate a questionnaire for my population, using a "think-aloud" (protocol analysis) method. The study looks at IT user satisfaction. Do you think my participants have to use the ...
0
votes
0answers
69 views

Principal component analysis, psychometrics, and number of items required

I saw that questions regarding sample sizes and PCA are asked here quite frequently. However, I was not able to find exactly the information I need. I plan to do a psychometric study and conduct a ...
0
votes
1answer
98 views

Eliminated items in Factor Analysis

I'd like to get your opinions on how to interpret items that had to be eliminated in factor analysis (FA). I've been researching consumer shopping motivations and ran a survey with 40 items, which ...
3
votes
0answers
198 views

What is the relationship between scale reliability measures (Cronbach's alpha etc.) and component/factor loadings?

Let's say I have a dataset with scores on a bunch of questionnaire items, which are theoretically comprised of a smaller number of scales, like in psychology research. I know a common approach here ...
1
vote
0answers
17 views

Is there an extension of multinomial process models that can model several dependent variables?

In the setting of psychological experiments, where a categorical response has to be given, the same response can, in theory, be generated by different latent processes. For example, in an experiment ...
6
votes
3answers
847 views

How to correctly interpret a parallel analysis in exploratory factor analysis?

Some scientific papers report results of parallel analysis of principal axis factor analysis in a way inconsistent with my understanding of the methodology. What am I missing? Am I wrong or are they. ...
3
votes
1answer
146 views

Why change items which don't change Cronbach Alpha?

I am doing peer review on a paper submission for a journal, and I am somewhat out of my depth. The authors are developing a psychometric scale. They did a pilot study with 45 items. They measured ...
0
votes
2answers
379 views

Neutral option on Likert Scale

I would like to know how do we analyze or regard the Neutral response (such as Don't Know) in a questionnaire using the following Likert Scale: 1:Strongly Disagree 2:Disagree 3:Don't Know 4:Agree ...
7
votes
2answers
2k views

How is the Spearman-Brown prophecy formula affected by questions of differing difficulties?

How are the results of the Spearman-Brown prophecy formula affected by having test questions of differing difficulties or raters who are easy or hard graders. One respected text says the S-B is ...
12
votes
2answers
780 views

What criteria must be met in order to conclude a 'ceiling effect' is occurring?

According to The SAGE Encyclopedia of Social Science Research Methods… [a] ceiling effect occurs when a measure possesses a distinct upper limit for potential responses and a large concentration ...
0
votes
0answers
55 views

Correlation significance test with standardized z scores

I am using spss I am looking at a criterion-validity concurrent design. I had to transform two groups performance ratings into z scores because there were differences in how raters rated them on the ...
0
votes
0answers
20 views

theoretical profile correlation

My data (n > 4000) contains the results of two separate tests (instruments). I have a profile made from likert scales for one of the instruments (S1, S2, ... S20). I want to find the corresponding ...
3
votes
0answers
93 views

How can IRT-Models be understood in GLM/ SEM Framework? (Predict Learning with added Paradata-Covariates)

I'll be working with data from an intelligent tutor system similar to one studied in the KDD-Cup 2010 on student performance prediction and plan to use IRT models to infer item and ability parameters. ...
6
votes
1answer
152 views

Item reliability or fit in IRT-based adaptive tests?

My background is in machine learning and statistics, but I am relatively new to psychometrics and testing. Nearly all of the literature I've found on item reliability refers to Chronbach's alpha or ...
2
votes
3answers
235 views

Can statistics really be used in education to determine test scores?

I am a middle school teacher. My district prides itself on having the kids take 3 tests during the year to predict their score, and my teaching, on "the real test" at the end of the year. My question: ...