Simple Pictures are Guttman's Ideal

"Simple routines have been established which require no knowledge of statistics, which take less time than the various manipulations now used by various investigators (such as critical ratios, biserial correlations, factor analysis, etc.), and which give a complete picture of the data not afforded by other techniques. The word `picture' might be interpreted here literally, for the results of the analysis are presented and easily assimilated in the form of a `scalogram', which at a glance gives the configuration of the qualitative data."

Guttman, Louis (1944) A basis for scaling qualitative data. American Sociological Review, 9:2, p.139

"These types [of person] could be shown in a chart (`a scalogram') where there is one row for each type of person and one column for each category of attribute [item] .... the scale analysis would establish an order among the rows and the columns." (ibid. p. 144)

False3 True2 False1 True3 False2 True1
x x x      
  x x x    
    x x x  
      x x x

In Guttman's original method, there is a separate column for each possible category of each attribute or item. Each column (attribute category) is checked for the presence or absence of that category for each person. Thus the column "False3" is checked if the person (row) responded false to attribute 3. Guttman uses cluster analysis by eye to reorder the rows and columns into a parallelogram:
"The `parallelogram' pattern in the chart, (such a chart, where one column is used for each category of an attribute, we call a scalogram), is necessary and sufficient for a set of dichotomous attributes to be expressible as simple functions of a single quantitative variable." (ibid. p. 144)

In later usage, each item is assigned only one column in the scalogram. Response category values are entered directly, so that the desired Scalogram pattern becomes a triangle. The conventional Scalogram orders the persons (rows) by raw score descending, and the items (columns) by raw score ascending.

Simple Pictures are Guttman's Ideal Guttman L. … Rasch Measurement Transactions, 1998, 12:3 p. 642.




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: Using Rasch Models in the Social, Behavioral, and Health Sciences, George Engelhard, Jr. 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

To be emailed about new material on www.rasch.org
please enter your email address here:

I want to Subscribe: & click below
I want to Unsubscribe: & click below

Please set your SPAM filter to accept emails from Rasch.org

www.rasch.org welcomes your comments:

Your email address (if you want us to reply):

 

ForumRasch Measurement Forum to discuss any Rasch-related topic

Go to Top of Page
Go to index of all Rasch Measurement Transactions
AERA members: Join the Rasch Measurement SIG and receive the printed version of RMT
Some back issues of RMT are available as bound volumes
Subscribe to Journal of Applied Measurement

Go to Institute for Objective Measurement Home Page. The Rasch Measurement SIG (AERA) thanks the Institute for Objective Measurement for inviting the publication of Rasch Measurement Transactions on the Institute's website, www.rasch.org.

Coming Rasch-related Events
July 30 - Nov., 2018Online Introduction to Classical and Rasch Measurement Theories (D.Andrich), University of Western Australia, Perth, Australia, http://www.education.uwa.edu.au/ppl/courses
Oct. 12 - Nov. 9, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 25 - Feb. 22, 2019, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 28, 2019 On-line course: Understanding Rasch Measurement Theory (ACER), https://www.acer.org/professional-learning/postgraduate/Rasch
April 4 - 8, 2019, Thur.-Mon. NCME annual meeting, Toronto, Canada.https://ncme.connectedcommunity.org/meetings/annual
April 5 - 9, 2019, Fri.-Tue. AERA annual meeting, Toronto, Canada.www.aera.net/Events-Meetings/Annual-Meeting
May 24 - June 21, 2019, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 28 - July 26, 2019, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
Aug. 9 - Sept. 6, 2019, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Oct. 11 - Nov. 8, 2019, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 24 - Feb. 21, 2020, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
May 22 - June 19, 2020, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 26 - July 24, 2020, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com
Aug. 7 - Sept. 4, 2020, Fri.-Fri. On-line workshop: Many-Facet Rasch Measurement (E. Smith, Facets), www.statistics.com
Oct. 9 - Nov. 6, 2020, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
June 25 - July 23, 2021, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Further Topics (E. Smith, Winsteps), www.statistics.com

 

The URL of this page is www.rasch.org/rmt/rmt1233.htm

Website: www.rasch.org/rmt/contents.htm