Table 23.3, 23.13, ... Item contrast

Please do not interpret this as a usual factor analysis. These plots show contrasts between opposing factors, not loadings on one factor. For more discussion, see dimensionality and contrasts.

 

The effect on the persons of the contrast between the oppositely loading items (Table 23.1)  at the top and bottom of the contrast plot is shown here.

 

Table 23.0 Variance components scree plot for items

Table 23.1, 23.11 Principal components plots of item loadings

Table 23.2, 23.12 Item Principal components analysis/contrast of residuals

Table 23.3, 23.13 Item contrast by persons

Table 23.4, 23.14 Item contrast loadings sorted by measure

Table 23.5, 23.15 Item contrast loadings sorted by entry number

Table 23.6, 23.16 Person measures for item clusters in contrast. Cluster Measure Plot for Table 23.6.

Table 23.99 Largest residual correlations for items

 

Responses by up to 9 persons (or on up to 9 items) to the items (or by the persons) with extreme positive loadings and the items (or persons) with extreme negative loadings are identified. These responses are seen to be higher, as expected, or lower than the model predicts. Counts of these are obtained for each person (or item). The persons (or items) showing the biggest impact of this contrast are listed first. Items and persons showing the most contrast are chosen for this Table based on the "Liking for Science" data.

 

Table 23.3 shows the impact of the first contrast in Table 23.1 on persons:

 

  ACT contrast 1 CONTRASTING RESPONSES BY PUPILS

+---------------------------------+

|          FAVORS TOP             |

| TOP 7 ACTS     | BOTTOM 7 ACTS  |

| HIGH  EXP. LOW | HIGH  EXP. LOW |     Persons scoring higher than expected on the top 7 items

+---------------------------------+

|    5    2    0 |    0    3    4 | 15  DYSON, STEPHIE NINA 

|    5    2    0 |    0    3    4 | 26  NEIMAN, RAYMOND

+---------------------------------+

+---------------------------------+

|          FAVORS BOTTOM          |

| TOP 7 ACTS     | BOTTOM 7 ACTS  |

| HIGH  EXP. LOW | HIGH  EXP. LOW |      Persons scoring higher than expected on the bottom 7 items

+---------------------------------+

|    0    3    4 |    0    7    0 | 8   LAMBERT, MD., ROSS W.

|    0    3    4 |    0    7    0 | 11  HSIEH, PAUL FRED

|    0    5    2 |    3    3    1 | 32  ROSSNER, JACK

|    0    3    4 |    0    7    0 | 51  REISS, STEVE

+---------------------------------+

 

FAVORS TOP

These persons score higher on the items at the top of the Contrast 1 plot in Table 23.1 than the items at the bottom of the contrast plot

FAVORS BOTTOM

These persons score higher on the items at the bottom of the Contrast 1 plot in Table 23.1 than the items at the top of the contrast plot

TOP 7 ACTS

Responses for the top 7 items (or top half of the items if less than 7) on the Contrast plot

BOTTOM 7 ACTS

Responses for the bottom 7 items (or top half of the items if less than 7) on the Contrast plot

HIGH

Person response is higher than expected on this many items

EXP.

Person response is expected (within 0.5 score points) on this many items

LOW

Person response is lower than expected on this many items

15  DYSON, STEPHIE NINA

Person entry number and person label.

Persons with greatest differential performance between TOP and BOTTOM are shown with strongest difference listed first.

15  DYSON, STEPHIE NINA

8   LAMBERT, MD., ROSS W.

The effect of the 1st Contrast is more strongly seen in the performance of these two persons. Is there something about them that interacts with the set of items?

 


Help for Winsteps Rasch Measurement Software: www.winsteps.com. Author: John Michael Linacre

The Languages of Love: draw a map of yours!

For more information, contact info@winsteps.com or use the Contact Form
 

Facets Rasch measurement software. Buy for $149. & site licenses. Freeware student/evaluation download
Winsteps Rasch measurement software. Buy for $149. & site licenses. Freeware student/evaluation download

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

 

Forum Rasch Measurement Forum to discuss any Rasch-related topic

Click here to add your email address to the Winsteps and Facets email list for notifications.

Click here to ask a question or make a suggestion about Winsteps and Facets software.

Rasch Publications
Rasch Measurement Transactions (free, online) Rasch Measurement research papers (free, online) Probabilistic Models for Some Intelligence and Attainment Tests, Georg Rasch Applying the Rasch Model 3rd. Ed., Bond & Fox Best Test Design, Wright & Stone
Rating Scale Analysis, Wright & Masters Introduction to Rasch Measurement, E. Smith & R. Smith Introduction to Many-Facet Rasch Measurement, Thomas Eckes Invariant Measurement with Raters and Rating Scales: Rasch Models for Rater-Mediated Assessments, George Engelhard, Jr. & Stefanie Wind Statistical Analyses for Language Testers, Rita Green
Rasch Models: Foundations, Recent Developments, and Applications, Fischer & Molenaar Journal of Applied Measurement Rasch models for measurement, David Andrich Constructing Measures, Mark Wilson Rasch Analysis in the Human Sciences, Boone, Stave, Yale
in Spanish: Análisis de Rasch para todos, Agustín Tristán Mediciones, Posicionamientos y Diagnósticos Competitivos, Juan Ramón Oreja Rodríguez
Winsteps Tutorials Facets Tutorials Rasch Discussion Groups

 


 

 
Coming Winsteps & Facets Events
May 22 - 24, 2018, Tues.-Thur. EALTA 2018 pre-conference workshop (Introduction to Rasch measurement using WINSTEPS and FACETS, Thomas Eckes & Frank Weiss-Motz), https://ealta2018.testdaf.de
May 25 - June 22, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 27 - 29, 2018, Wed.-Fri. Measurement at the Crossroads: History, philosophy and sociology of measurement, Paris, France., https://measurement2018.sciencesconf.org
June 29 - July 27, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
July 25 - July 27, 2018, Wed.-Fri. Pacific-Rim Objective Measurement Symposium (PROMS), (Preconference workshops July 23-24, 2018) Fudan University, Shanghai, China "Applying Rasch Measurement in Language Assessment and across the Human Sciences" www.promsociety.org
Aug. 10 - Sept. 7, 2018, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Oct. 12 - Nov. 9, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com

 

 

Our current URL is www.winsteps.com

Winsteps® is a registered trademark
 


 
John "Mike" L.'s Wellness Report: I'm 72, take no medications and, March 2018, my doctor is annoyed with me - I'm too healthy!
According to Wikipedia, the human body requires about 30 minerals, maybe more. There are 60 naturally-occurring minerals in the liquid Mineral Supplement which I take daily.