Calculate expected scores

Source: R/calc_escore_functions.r

calcEscore is a function for calculating expected scores.

calcEscore(object, theta)

# S4 method for class 'item_1PL,numeric'
calcEscore(object, theta)

# S4 method for class 'item_2PL,numeric'
calcEscore(object, theta)

# S4 method for class 'item_3PL,numeric'
calcEscore(object, theta)

# S4 method for class 'item_PC,numeric'
calcEscore(object, theta)

# S4 method for class 'item_GPC,numeric'
calcEscore(object, theta)

# S4 method for class 'item_GR,numeric'
calcEscore(object, theta)

# S4 method for class 'item_pool,numeric'
calcEscore(object, theta)

# S4 method for class 'item_1PL,matrix'
calcEscore(object, theta)

# S4 method for class 'item_2PL,matrix'
calcEscore(object, theta)

# S4 method for class 'item_3PL,matrix'
calcEscore(object, theta)

# S4 method for class 'item_PC,matrix'
calcEscore(object, theta)

# S4 method for class 'item_GPC,matrix'
calcEscore(object, theta)

# S4 method for class 'item_GR,matrix'
calcEscore(object, theta)

# S4 method for class 'item_pool,matrix'
calcEscore(object, theta)

# S4 method for class 'item_pool_cluster,numeric'
calcEscore(object, theta)

Arguments

object

an item or an item_pool object.

theta

theta values to use.

Value

item object:

calcEscore a vector containing expected score of the item at the theta values.

item_pool object:

calcEscore returns a vector containing the pool-level expected score at the theta values.

References

Rasch, G. (1960). Probabilistic models for some intelligence and attainment tests. Copenhagen: Danish Institute for Educational Research.

Lord, F. M. (1952). A theory of test scores (Psychometric Monograph No. 7). Richmond, VA: Psychometric Corporation.

Birnbaum, A. (1957). Efficient design and use of tests of mental ability for various decision-making problems (Series Report No. 58-16. Project No. 7755-23). Randolph Air Force Base, TX: USAF School of Aviation Medicine.

Birnbaum, A. (1958). On the estimation of mental ability (Series Report No. 15. Project No. 7755-23). Randolph Air Force Base, TX: USAF School of Aviation Medicine.

Birnbaum, A. (1958). Further considerations of efficiency in tests of a mental ability (Series Report No. 17. Project No. 7755-23). Randolph Air Force Base, TX: USAF School of Aviation Medicine.

Birnbaum, A. (1968). Some latent trait models and their use in inferring an examinee's ability. In Lord, F. M., Novick, M. R. (eds.), Statistical Theories of Mental Test Scores, 397-479. Reading, MA: Addison-Wesley.

Masters, G. N. (1982). A Rasch model for partial credit scoring. Psychometrika, 47(2), 149-174.

Andrich, D. (1978). A rating formulation for ordered response categories. Psychometrika, 43(4), 561-573.

Muraki, E. (1992). A generalized partial credit model: Application of an EM algorithm. Applied Psychological Measurement, 16(2), 159-176.

Samejima, F. (1969). Estimation of latent ability using a response pattern of graded scores. Psychometrika Monograph, 17.

Examples

item_1     <- new("item_1PL", difficulty = 0.5)
item_2     <- new("item_2PL", slope = 1.0, difficulty = 0.5)
item_3     <- new("item_3PL", slope = 1.0, difficulty = 0.5, guessing = 0.2)
item_4     <- new("item_PC", threshold = c(-1, 0, 1), ncat = 4)
item_5     <- new("item_GPC", slope = 1.2, threshold = c(-0.8, -1.0, 0.5), ncat = 4)
item_6     <- new("item_GR", slope = 0.9, category = c(-1, 0, 1), ncat = 4)

ICC_item_1 <- calcEscore(item_1, seq(-3, 3, 1))
ICC_item_2 <- calcEscore(item_2, seq(-3, 3, 1))
ICC_item_3 <- calcEscore(item_3, seq(-3, 3, 1))
ICC_item_4 <- calcEscore(item_4, seq(-3, 3, 1))
ICC_item_5 <- calcEscore(item_5, seq(-3, 3, 1))
ICC_item_6 <- calcEscore(item_6, seq(-3, 3, 1))
TCC_pool   <- calcEscore(itempool_science, seq(-3, 3, 1))