Results

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale.
[3]

 

Item Statistics
 Proportion
 

 

[3]

Wright Map

[4]

Differential Item Functioning

Welcome to DIF Rasch Model.

Each variable should be coded as 0 or 1 with the 'Grouping variable'in jamovi.

The focal group should be coded as 1.

The Raju's Z statistics are estimated by Marginal Maximum Likelihood Estimation(MMLE),and area method is obtained by using the unsigned areas between the ICCs.

Feature requests and bug reports can be made on my GitHub.

Raju’s area method
 StatisticAdj.pdeltaRajuEffect size
 

 

[6]

[5]

Dichotomous Rasch Model

Argument 'vars' contains 'ER8' which is not present in the dataset

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 
scale
[3]

 

Item Statistics
 Proportion
ER1.
ER2.
ER3.
ER4.
ER5.
ER6.
ER7.
ER8.
[3]

 

Wright Map

[4]

Expected Score Curve

ER1

ER2

ER3

ER4

ER5

ER6

ER7

ER8

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale-0.556
[3]

 

Item Statistics
 Proportion
ER50.233
ER60.534
[3]

 

Wright Map

[4]

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale0.477
[3]

 

Item Statistics
 Proportion
ER10.671
ER20.507
ER30.726
ER40.315
ER50.233
ER60.534
ER70.342
[3]

 

Wright Map

[4]

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale0.477
[3]

 

Item Statistics
 Proportion
ER60.671
ER70.507
ER50.726
ER40.315
ER30.233
ER20.534
ER10.342
[3]

 

Wright Map

[4]

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale0.477
[3]

 

Item Statistics
 Proportion
ER10.671
ER20.507
ER30.726
ER40.315
ER50.233
ER60.534
ER70.342
[3]

 

Wright Map

[4]

Dichotomous Rasch Model

Each variable must be coded as 0 or 1 with the type of numeric-continuous in jamovi.

The result tables are estimated by Marginal Maximum Likelihood estimation(MMLE).

The rationale of snowIRT module is described in the documentation.

Feature requests and bug reports can be made on my GitHub.

Model Fit
 Person Reliability
scale0.477
[3]

 

Item Statistics
 Proportion
ER20.671
ER40.507
ER30.726
ER10.315
ER50.233
ER60.534
ER70.342
[3]

 

Wright Map

[4]

[5]

References

[1] The jamovi project (2020). jamovi. (Version 1.2) [Computer Software]. Retrieved from https://www.jamovi.org.

[2] R Core Team (2019). R: A Language and environment for statistical computing. (Version 3.6) [Computer software]. Retrieved from https://cran.r-project.org/.

[3] Robitzsch,A., Kiefer, T., & Wu, M. (2020). TAM: Test Analysis Modules. [R package]. Retrieved from https://CRAN.R-project.org/package=TAM.

[4] Martinkova, P., & Drabinova, A. (2018). ShinyItemAnalysis: for teaching psychometrics and to enforce routine analysis of educational tests. [R package]. Retrieved from https://CRAN.R-project.org/package=ShinyItemAnalysis.

[5] Seol, H. (2020). snowIRT: Item Response Theory for jamovi. [jamovi module]. Retrieved from https://github.com/hyunsooseol/snowIRT.

[6] Magis, D., Beland, S., Tuerlincks, F., & De Boeck, P. (2010). difR: A general framework and an R package for the detection of dichotomous differential item functioning. [R package]. Retrieved from https://CRAN.R-project.org/package=difR.