|
Mixed rating scale (partial credit) forms and MCQ scoring keys |
Top Up Down
A A |
Facets handles mixtures of rating scales and partial credit items within the same test easily using Models=. Datasets containing only MCQ items can be analyzed.
Items 1-10 are dichotomies, already scored 0,1
Items 11-14 are 3-category rating scales 1,2,3 - each with its own scale definition, i.e., partial credit items.
Items 15 is a binomial count 0-10 successes
Facet 1 is person, Facet 2 is judge (only for items 11-14), Facet 3 is item:
Models=
?, X, 1-10, D ; items 1-10 -dichotomies - no judge
?, ?, 11-14#,R3 ; items 11-14 - each with own scale
?, X, 15, B10 ; item 15 - 10 binomial trials
*
Here are typical lines of data for person 23:
data=
23,0,1-10,0,1,1,1,1,0,0,0,1,1 ; person 23, with no judge, responds to items 1-10, scored 0 or 1.
23,3,11-14,3,2,3,1 ; person 23, judge 3, rated on items 11-14 on rating scales with highest category 3.
23,6,12-14,1,,3 ; person 23, judge 6, rates only items 12 and 14
23,0,15,7 ; person 23, no judge, 7 successes out of 10 binomial trials.
To score multiple-choice MCQ dichotomies:
The scoring key for the 10 items is: CADBDCDABB
Also shown are items 11-14 which are partial credit or rating scale items.
Item 15 is a binomial trial item giving successes out of 10.
Models=
?,X,1,C ; using scoring key C as the model code
?,X,2,A
?,X,3,D
?,X,4,B
?,X,5,D
?,X,6,C
?,X,7,D
?,X,8,A
?,X,9,B
?,X,10,B
?, ?, 11-14#,R3 ; items 11-14 - each with own scale
?, X, 15, B10 ; item 15 - 10 binomial trials
*
Rating (or partial credit) scale=A,D ; Scale A - dichotomous
0=Wrong,,,B+C+D+ ; add other possible wrong responses here
1=Right,,,A ; ",,," is to skip over anchor value positions
*
Rating (or partial credit) scale=B,D
0=Wrong,,,A+C+D+. ; add other possible wrong responses here
1=Right,,,B
*
Rating (or partial credit) scale=C,D
0=Wrong,,,A+B+D+. ; add other possible wrong responses here
1=Right,,,C
*
Rating (or partial credit) scale=D,D
0=Wrong,,,A+B+C+. ; add other possible wrong responses here
1=Right,,,D
*
Here are typical lines of data for person 23:
data=
23,0,1-10,D,B,C,A,.,D,A,B,D,C ; person 23, with no judge, responds to items 1-10
23,3,11-14,3,2,3,1 ; person 23, judge 3, rated on items 11-14
23,6,12-14,1,,3 ; person 23, judge 6, rates only items 12 and 14
23,0,15,7 ; person 23, no judge, 7 successes out of 15.
Help for Facets Rasch Measurement Software: www.winsteps.com.