IRTpp (version 0.2.6.1)

probability.1pl: 1PL probability function

Description

The probability function in the 1PL model.

Usage

probability.1pl(z, b = z$b, theta)

Arguments

z

Optional. A list with the parameter b specified by keys.

b

The difficulty parameter. (Optional if d is specified)

theta

The subject's latent trait.

Value

Tue value of the probability for the model 1pl.

See Also

probability.2pl, probability.3pl, prob.3pl, prob.2pl

Examples

## Simulate the test
# data <- simulateTest(model = "1PL", items = 20, individuals = 200)
## item parameters
# zita <-data$itempars
## Latent traits
# thetas <- data$latentTraits
## Probability model
# probability.1pl(zita, theta = thetas)