Note: Input values (either numeric or character) must be separated by tabs. Copy and paste from Excel/Numbers.

Please make sure that your data includes the header (variable names) in the first row.


                
                

If you need to create 1-0 data first, use Binary (1-0) Data Converter .


Basic statistics (Using the raw score)


                

Histogram of the total score (Using the raw score)


Boxplot (Using the raw score)


Cronbach's coefficient alpha (Using the raw score)


                

Drop if: Cronbach alpha when the item is removed
r dropped: item-total correlation without the item
r: item-total (point-biserial) correlation
IF: item facility or item mean (proportion correct answers)
ID: item discrimination (upper 1/3 - lower 1/3)


Item estimate


                

Person estimate (Theta)


                

Plots



R session info

              

Note: Input values (either numeric or character) must be separated by tabs. Copy and paste from Excel/Numbers.

Please make sure that your data includes the header (variable names) in the first row.


                
                

Basic statistics (Using the raw score)


                

Histogram


Box plot with individual data points


Cronbach's coefficient alpha (Using the raw score)


                

Drop if: Cronbach alpha when the item is removed
r dropped: item-total correlation without the item
r: item-total (point-biserial) correlation




Item estimate


                

Person estimate


                

Plots





R session info

              
Note

This web application is developed with Shiny.


List of Packages Used
library(shiny)
library(shinyAce)
library(psych)
library(CTT)
library(ltm)
library(beeswarm)
library(parallel)


Code

Source code for this application is based on "The handbook of Research in Foreign Language Learning and Teaching" (Takeuchi & Mizumoto, 2012). I also referred to the code used in MacR.

The code for this web application is available at GitHub.

If you want to run this code on your computer (in a local R session), run the code below:
library(shiny)
runGitHub("irt","mizumot")


Citation in Publications

Mizumoto, A. (2015). Langtest (Version 1.0) [Web application]. Retrieved from http://langtest.jp


Article

Mizumoto, A., & Plonsky, L. (2015). R as a lingua franca: Advantages of using R for quantitative research in applied linguistics. Applied Linguistics, Advance online publication. doi:10.1093/applin/amv025


Recommended

To learn more about R, I suggest this excellent and free e-book (pdf), A Guide to Doing Statistics in Second Language Research Using R, written by Dr. Jenifer Larson-Hall.

Also, if you are a cool Mac user and want to use R with GUI, MacR is defenitely the way to go!


Author

Atsushi MIZUMOTO, Ph.D.
Professor of Applied Linguistics
Faculty of Foreign Language Studies /
Graduate School of Foreign Language Education and Research,
Kansai University, Osaka, Japan