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Questions tagged [mirt]

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Item Response Theory (IRT) -- Problem (?) or unxepected result using the mirt package with a 2PL model for binary variables?

I'm working with 5 variables related to "child and family health" using Item Response Theory to check the model and identify its parameters. My model is composed of items such as "Do ...
Luis's user avatar
  • 143
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1 answer
120 views

$M_2$ Function in MIRT R Package

I am facing an error. The $M_2$ function is throwing an error when I have three items in a test. How can I resolve this?
user22151754's user avatar
2 votes
1 answer
69 views

Repeating the same item with different offsets using the *mirt* package

Let's imagine that we want to develop an IRT model that describes the probability that a basketball player scores a basket when he shoots the ball from a certain distance. Distance is a continuous ...
Daniel Dostal's user avatar
0 votes
0 answers
27 views

Get random effect value from pattern of data

Rasch models are typically fit through an item response theory framework, but can also be estimated through a mixed effects model (e.g., see here). This is highly useful in my case because of some of ...
Daniel Anderson's user avatar
0 votes
0 answers
112 views

Longitudinal IRT model specification using MIRT bfactor function

I try to specify / calculate a longitudinal IRT latent growth model to compare learning gains between three school years in a large data set. The test were administered by a computer adaptive testing ...
fgrng's user avatar
  • 31
0 votes
0 answers
54 views

Python implementation of Marginal Maximum Likelihood estimate based 2-PL Dichotomous IRT

I am looking for implementations of simple Marginal Maximum Likelihood Estimate based 2-PL IRT Item estimation in Python. Any relevant Python libraries that do this (similar to snowIRT module in ...
204's user avatar
  • 121
1 vote
0 answers
17 views

Must questionnaire questions have the same number of options for IRT models to work?

Given a questionnaire whose questions have different numbers of options available say having questions with ratings from 1-2 and 1-5. Could I use polytomous models such as a partial credit model to ...
darzan's user avatar
  • 21
1 vote
0 answers
462 views

Fixing item parameters in MIRT

I am trying to estimate a multiple group model where I fix some of the item parameters and estimate the rest. I was expecting that this scenario would allow me to remove the restriction on the ...
Tzur Karelitz's user avatar
2 votes
0 answers
160 views

Estimating a higher-oder IRT model in R

Hi everyone, I am trying to estimate a higher-order model with the mirt package in R. I have already conducted an analysis using ...
Nicolas N.'s user avatar
1 vote
0 answers
79 views

Confidence Interval for factor loadings of 2PL model

I estimated a 2PL model obtained for some dichotomous data presenting answers of 12 "yes/no" questions from about 200 individuals. Now I want to calculate the confidence intervals for the ...
mugdi's user avatar
  • 90
1 vote
0 answers
251 views

Computing IRT score reliability across a range of ability in mirt

I am using mirt and would like to get reliability estimates across a range of ability for a 1-factor scale. Essentially, I would like to extract the data used to ...
joshlangfus's user avatar
0 votes
0 answers
28 views

How do I calculate different reliabilty levels of theta when standard error of theta is known? (IRT-model) [duplicate]

I've recently seen a plot where the level of reliability is given for different SE values of theta estimates: I have also plotted the standard errors of theta as a function of theta but now I am ...
C K's user avatar
  • 51
1 vote
1 answer
205 views

Calculation of reliability of scale scores in an IRT- model

While trying to compute the reliability of scale scores obtained from IRT models (bifactor models and unidimensional models) I was wondering why there are so many published papers who report omega ...
C K's user avatar
  • 51
0 votes
0 answers
146 views

mirt: GRM with symmetrical thresholds

I'm looking for a way to fit a graded response model where the thresholds are symmetrically located around zero. The mirt.model command allows you to add an ...
Daniel Dostal's user avatar