Science {mirt}

R Documentation

Description of Science data

Description

A 4-item data set borrowed from ltm package in R, first example of the grm() function. See more complete documentation therein.

Author(s)

Phil Chalmers rphilip.chalmers@gmail.com

References

Chalmers, R., P. (2012). mirt: A Multidimensional Item Response Theory Package for the R Environment. Journal of Statistical Software, 48(6), 1-29. doi:10.18637/jss.v048.i06

Examples

## No test: 
itemstats(Science)

## $overall
##    N mean_total.score sd_total.score ave.r  sd.r alpha
##  392           11.668          2.003 0.275 0.098 0.598
## 
## $itemstats
##           N  mean    sd total.r total.r_if_rm alpha_if_rm
## Comfort 392 3.120 0.588   0.596         0.352       0.552
## Work    392 2.722 0.807   0.666         0.332       0.567
## Future  392 2.990 0.757   0.748         0.488       0.437
## Benefit 392 2.837 0.802   0.684         0.363       0.541
## 
## $proportions
##             1     2     3     4
## Comfort 0.013 0.082 0.679 0.227
## Work    0.084 0.250 0.526 0.140
## Future  0.036 0.184 0.536 0.245
## Benefit 0.054 0.255 0.492 0.199

mod <- mirt(Science, 1)
plot(mod, type = 'trace')

## End(No test)

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