This is a small data set of multiplication item responses. This data contains responses to 4 items from 142 respondents, which ask respondents to complete an integer multiplication problem.

## Format

`mdm_data`

is a tibble containing responses
to multiplication items, as described in MacReady & Dayton (1977). There are
142 rows and 5 variables.

`respondent`

: Respondent identifier`mdm1`

-`mdm4`

: Dichotomous item responses to the 4 multiplication items

`mdm_qmatrix`

is a tibble that identifies
which skills are measured by each MDM item. This MDM data contains 4 items,
all of which measure the skill of multiplication. The `mdm_qmatrix`

correspondingly is made up of 4 rows and 2 variables.

`item`

: Item identifier, corresponds to`mdm1`

-`mdm4`

in`mdm_data`

`multiplication`

: Dichotomous indicator for whether or not the multiplication skill is measured by each item. A value of`1`

indicates the skill is measured by the item and a value of`0`

indicates the skill is not measured by the item.

## References

MacReady, G. B., & Dayton, C. M. (1977). The use of probabilistic
models in the assessment of mastery. *Journal of Educational Statistics,
2*(2), 99-120. doi:10.2307/1164802