What is included:
- data simulation under the Two-Parameter Logistic Model (Samejima, 1969) and the Graded Response Model (van der Linden & Hambleton, 2013)
- latent trait estimation and standard errors using the following methods: Weighted Maximum Likelihood, Maximum Likelihood, and Expected A Posteriori
- Reliable Change Index (Jacobson & Truax, 1991) computation using the following methods: Wald Test, ...
- Person-Fit Statistic
lz(Drasgow, Levine, & Williams, 1985) using the corrected versions for both dichotomous (Snijders, 2001) and polychotomous (Sinharay, 2016) items
Exported functions:
simulateirt(theta, difficulty, slope)estimateirt(data, theta.method = "WLE")changeirt()personfit()
References:
- Drasgow, F., Levine, M. V., & Williams, E. A. (1985). Appropriateness measurement with polychotomous item response models and standardized indices. British Journal of Mathematical and Statistical Psychology, 38(1), 67–86. http://doi.org/10.1111/j.2044-8317.1985.tb00817.x
- Jacobson, N. S., & Truax, P. (1991). Clinical significance: A statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology, 59(1), 12–19. http://doi.org/10.1037/0022-006X.59.1.12
- Samejima, F. (1969). Estimation of latent ability using a response pattern of graded scores. Psychometrika Monograph Supplement. Retrieved from http://psycnet.apa.org/psycinfo/1972-04809-001
- Sinharay, S. (2016). Asymptotically Correct Standardization of Person-Fit Statistics Beyond Dichotomous Items. Psychometrika, 81(4), 992–1013. http://doi.org/10.1007/s11336-015-9465-x
- Snijders, T. A. B. (2001). Asymptotic null distribution of person fit statistics with estimated person parameter. Psychometrika, 66(3), 331–342. http://doi.org/10.1007/BF02294437
- van der Linden, W. J., & Hambleton, R. K. (2013). Handbook of modern item response theory. Springer Science & Business Media.
under development...