itemgen {QAIG} | R Documentation |
Automatic item generator from a parent item model.
Description
itemgen
function generates group of sibling items from a
parent item model defined by user.
Usage
itemgen(stem_text = stem_text, formulae = formulae, N = N, C,
options_affix, ans_key, save.csv)
Arguments
stem_text |
The stem of the parent item with specified number-variables and character-variables. |
formulae |
A raw text that contains necessary formulae for the options (response choices) along with necessary values or functions that help to calculate the numeric value for each option. |
N |
A list of numeric input vector(s) for the number variable(s) in the stem. |
C |
(Optional) A list of character input vector(s) for the character variable(s) in the stem if there is any. |
options_affix |
(Optional) A list that consists of vectors with prefixes and suffixes (if there is any) of the numeric values in the options along with any text that can be included as an option of the items. |
ans_key |
(Optional) A text that indicates the correct response if it is NOT specified within formulae by '~'. |
save.csv |
(Optional) A name text given by the user for the output .csv file, if user wants to save the newly generated sibling items in working directory as a data.frame. |
Details
User has to develop a short schema for the parent item model that contains
formation of stem along with formula for each of the response choices of the parent
item as the input. Number-variables and character-variables must be specified in
particular manner in the stem. Each formula must be written in new line as text and
should be declared together as an object. itemgen
function delivers the changes
in the positions of the variables in stem and calculates the response choices
automatically by taking members from the input vectors given by user in the schema.
As a result, several permutations of changes in the variables lead to generation of
new group of items. Please see vignette of 'QAIG' for more details.
Value
This function returns a data frame that contains stem, options, answer
key etc. for all the generated sibling items within its rows to display in console
and within its columns in the saved .csv file if the input for the argument 'save.csv'
is given in itemgen
function.
Note
The formula model for each option must be distinct. itemgen
function
does NOT permit same numeric value as two or more response choices and hence it will
throw an error. If same numeric value needs to be produced as more than one
response choices, those models can be made different by adding 0 or multiplying 1
with the terms in the model.
The model for the distractor options in formulae must be written using "?".
Correct response option can be written using EITHER "~" OR "?". In OR case correct
response must be indicated by the function argument "ans_key" to stop itemgen
function throw an error. Please see section 2 and 3 in vignette of 'QAIG'.
Author(s)
Shubh Patra and Bao Sheng Loe
References
Gierl, M. J., Lai, H. (2011). The Role of Item Models in Automatic Item Generation.
Embretson, S. E., Kingston, N. M. (2018). Automatic Item Generation: A More Efficient Process for Developing Mathematics Achievement Items?
Examples
stem_text <- "The sum value of all the odd [C1] between [N1] and [N2] is"
n1 <- c(20, 24, 28, 32)
n2 <- c(48, 52, 56)
c1 <- c("natural numbers", "integers")
N <- list(n1 = n1, n2 = n2)
C <- list(c1 = c1)
formulae <- "Option_A ? sum((n1+1) : (n2-1))/2
Option_B ~ (length(seq(n1+1, n2-1, by = 2)))*(n1+n2)/2
Option_C ? sum(n1 : n2)/2
Option_D ? (length(seq(n1, n2, by = 2)))*(n1+n2)/2
"
options_affix <- list(Option_A = c("", ""), Option_B = c("", ""), Option_C = c("", ""),
Option_D = c("", ""), Difficulty = "MEDIUM")
# itemgen() function can be used as:
itemgen(stem_text = stem_text, formulae = formulae, N = N, C = C, options_affix = options_affix)