Cut-off points |
This is for 32-bit Facets 3.87. Here is Help for 64-bit Facets 4
Setting pass-fail cut-off points requires a precise conceptualization of the cut-off point. There are many possible conceptualizations. Here is one that is usually easy to explain:
In the "Essays" example, we want a cut-off point for the examinees between "5" and "6" on the rating scale.
So let's conceptualize this as:
"1,000 examinees whose performance is at the cut-off point between 5 and 6 would have an average rating of 5.5 on a "standard" (average) essay when rated by a standard (average) reader."
Table 7.2.1 Essay Measurement Report (arranged by MN).
-------------------------------------------------------------------------------------------------
| Obsvd Obsvd Obsvd Fair-M| Model | Infit Outfit |Estim.| |
| Score Count Average Avrage|Measure S.E. | MnSq ZStd MnSq ZStd|Discrm| N Essay |
-------------------------------------------------------------------------------------------------
| 1843.0 384.0 4.8 4.73| .00 .04 | 1.00 -.2 .99 -.3| | Mean (Count: 3) |
Table 7.3.1 Reader Measurement Report (arranged by MN).
----------------------------------------------------------------------------------------------------------------
| Obsvd Obsvd Obsvd Fair-M| Model | Infit Outfit |Estim.| Exact Agree. | |
| Score Count Average Avrage|Measure S.E. | MnSq ZStd MnSq ZStd|Discrm| Obs % Exp % | Nu Reader |
----------------------------------------------------------------------------------------------------------------
| 460.8 96.0 4.8 4.73| .00 .08 | 1.00 -.1 .99 -.2| | | Mean (Count: 12) |
According to Table 7:
The average difficulty of the essays is 0.00 - this would be the "standard" essay difficulty
The average reader has a severity/leniency of 0.00
According to Table 8:
Table 8.1 Category Statistics.
--------------------------------------------------------------------------------------------------
| DATA | QUALITY CONTROL |RASCH-ANDRICH| EXPECTATION | MOST |.5 Cumul.| Cat|
| Category Counts Cum.| Avge Exp. OUTFIT| THRESHOLDS | Measure at |PROBABLE|Probabil.|PEAK|
|Score Used % % | Meas Meas MnSq |Measure S.E.|Category -0.5 | from | at |Prob|
--------------------------------------------------------------------------------------------------
| 5 232 20% 66%| -.01 .00 1.0 | .04 .07| .05 -.24| .04 | -.17 | 27%|
| 6 207 18% 84%| .24 .22 1.0 | .23 .07| .61 .33| .23 | .32 | 29%|
A rating of 5.5 on the rating scale has a Rasch-Andrich threshold (step calibration) of 0.33 [see "EXPECTATION at -0.5" for category 6 in Table 8]
So the cut-off level for 7 to 8 is (0.0 + 0.0 + 0.33) = 0.33 logits.
You can check this by looking at the "Fair Average" column in Table 7 for the examinees. Look for a candidate with a fair average close to 5.5. The candidate measure should be close to 0.33.
Table 7.1.1 examinee Measurement Report (arranged by MN).
-------------------------------------------------------------------------------------------------
| Obsvd Obsvd Obsvd Fair-M| Model | Infit Outfit |Estim.| |
| Score Count Average Avrage|Measure S.E. | MnSq ZStd MnSq ZStd|Discrm| Nu examinee |
-------------------------------------------------------------------------------------------------
| 198 36 5.5 5.50| .33 .12 | 1.17 .8 1.17 .8| .70 | 8 8 |
Help for Facets Rasch Measurement and Rasch Analysis Software: www.winsteps.com Author: John Michael Linacre.
Facets Rasch measurement software.
Buy for $149. & site licenses.
Freeware student/evaluation Minifac download Winsteps Rasch measurement software. Buy for $149. & site licenses. Freeware student/evaluation Ministep download |
---|
Forum: | Rasch Measurement Forum to discuss any Rasch-related topic |
---|
Questions, Suggestions? Want to update Winsteps or Facets? Please email Mike Linacre, author of Winsteps mike@winsteps.com |
---|
State-of-the-art : single-user and site licenses : free student/evaluation versions : download immediately : instructional PDFs : user forum : assistance by email : bugs fixed fast : free update eligibility : backwards compatible : money back if not satisfied Rasch, Winsteps, Facets online Tutorials |
---|
Coming Rasch-related Events | |
---|---|
May 17 - June 21, 2024, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
June 12 - 14, 2024, Wed.-Fri. | 1st Scandinavian Applied Measurement Conference, Kristianstad University, Kristianstad, Sweden http://www.hkr.se/samc2024 |
June 21 - July 19, 2024, Fri.-Fri. | On-line workshop: Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com |
Aug. 5 - Aug. 7, 2024, Mon.-Wed. | 2024 Inaugural Conference of the Society for the Study of Measurement (Berkeley, CA), Call for Proposals |
Aug. 9 - Sept. 6, 2024, Fri.-Fri. | On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com |
Oct. 4 - Nov. 8, 2024, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
Jan. 17 - Feb. 21, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
May 16 - June 20, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
June 20 - July 18, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Further Topics (E. Smith, Facets), www.statistics.com |
Oct. 3 - Nov. 7, 2025, Fri.-Fri. | On-line workshop: Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com |
Our current URL is www.winsteps.com
Winsteps® is a registered trademark