ISELECT= item selection criterion = *, all items

Items to be selected may be specified by using the ISELECT= instruction to match characters within the item name. Items deleted by IDELETE= or IDFILE= are never selected by ISELECT=.

 

This can be done before analysis in the control file or with "Extra specifications". It can also be done after the analysis using the "Specification" pull-down menu.

 

Selection rules:

Control characters match label or name. They start at the first column of the label or name.

?

matches any character

*

matches any string of characters - must be last selection character.

If * is in the first column, then every available person or item is selected.

A

matches A in the person label, and similarly all other characters except { }

{..}

braces characters which can match a single character: {ABC} matches A or B or C.

{.. - ..}

matches single characters in a range. {0-9} matches digits in the range 0 to 9.

{.. --..}

matches a single "-" {AB--} matches A or B or "-".

{~ABX}

omits persons or items which match A or B or X

@fieldname=

positions the next selection character at the start of the specified field

 

Each ISELECT= performed using the "Specification" pull-down menu selects from all those analyzed. For incremental selections from the Specification menu, i.e., selecting from those already selected, specify +ISELECT=

 

Example 0: In Example 10, select bank 6:

@BANK=5 ; Bank number is in column 5 of the item label

ISELECT=@BANK=6

 

Example 1: Select for analysis only items with M in the 5th column of item name.

ISELECT=????M* M in column means Math items

0001M 2x4 ; selected

0002R the cat ; omitted

END NAMES

 

Example 2: Select for analysis all items with code "A 4" in columns 2-4 of their names.

ISELECT="?A 4*" quotes because a blank is included. A is in col. 2 etc.

ZA 4PQRS selected

 

Example 3: Select all Math (M in column 2) items which are Addition or Division (A or D in column 4):

ISELECT="?M?{AD}*"

1M3A456 2+2  selected

1M5D689 23/7  selected

1H2A123 George omitted (History, American)

 

Example 3: Select codes A, 1,2,3,4,5,6 in column 3:

ISELECT=??{A1-6}*

 

Example 4: Select "- " in columns 2 and 3:

ISELECT="?- "

 

Example 5: Select "-" or "x" in column 2 with " " in column 3:

ISELECT="?{--x} "

 

Example 6: Analyze only math (column 4 or person-id). Then report only items in Topic C (column 1). Then only report items in Strands 4 and 5 (column 2) in Topic C.

 

ISELECT=???M* in the Control file or at the Extra Specifications prompt.

ISELECT=C*  using the Specification pull-down menu, after the analysis

+ISELECT=?{45}* using the Specification pull-down menu.

 

Example 7: 4 forms in one analysis with common items. Produce a score table for each form.

In the item labels, columns 1-4 of item label are form indicator. Items can be in more than one form

1xxx for form1 items

12xx for form 1 and 2 items

xx3x for form 3

xx34 for form 3 and 4

etc.

 

Then, use the Specification menu box:

ISELECT = 1??? will select all items on form 1

Output Tables: Table 20 score table

ISELECT = * select all items

ISELECT = ?2?? will select all items on form 2

etc.

 

Example 8: Omit unwanted items, marked by "x" in the first character of the item label:

ISELECT={~x}

 

Example 9: If the field to be selected is already identified, then this simplifies counting the column:

@Dx = 16E17 ; $C44W2

16E17 means that the field is in columns 16 and 17 of the item label. Look at a data record to see what is actually there.

ISELECT=???????????????23 ; selects "23" in columns 16 and 17 of the item label

 

Example 10: We want item type group X (in column 4 of the item label) except for sub-types 11, 24 (in columns 6, 7 of the item label):

ISELECT = "???X?{12}{14}"  ; this selects X and 11, 14, 21, 24

EDFILE=*

"?" "?????14" . ; convert 14 to missing data

"?" "?????21" . ; convert 21 to missing data

*

 

Example 11: multiple levels in the Specification menu box:

Between each step, in the Specification menu box, please specify ISELECT=   (nothing) to reinstate all the items.

 

Example using Example0.txt and the Specification menu box:

 

iselect=L

"ISELECT=L*" selected 5 ACT

CURRENTLY REPORTABLE ACT = 5

 

iselect=W

"ISELECT=W*" selected 0 ACT

CURRENTLY REPORTABLE ACT = 5

... not done

 

iselect=

"ISELECT=*" selected 25 ACT

CURRENTLY REPORTABLE ACT = 25

 

iselect=W

"ISELECT=W*" selected 7 ACT

CURRENTLY REPORTABLE ACT = 7


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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 Rasch-related Events
Jan. 5 - Feb. 2, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com
Jan. 10-16, 2018, Wed.-Tues. In-person workshop: Advanced Course in Rasch Measurement Theory and the application of RUMM2030, Perth, Australia (D. Andrich), Announcement
Jan. 17-19, 2018, Wed.-Fri. Rasch Conference: Seventh International Conference on Probabilistic Models for Measurement, Matilda Bay Club, Perth, Australia, Website
Jan. 22-24, 2018, Mon-Wed. In-person workshop: Rasch Measurement for Everybody en español (A. Tristan, Winsteps), San Luis Potosi, Mexico. www.ieia.com.mx
April 10-12, 2018, Tues.-Thurs. Rasch Conference: IOMW, New York, NY, www.iomw.org
April 13-17, 2018, Fri.-Tues. AERA, New York, NY, www.aera.net
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
Sept. 3 - 6, 2018, Mon.-Thurs. IMEKO World Congress, Belfast, Northern Ireland www.imeko2018.org
Oct. 12 - Nov. 9, 2018, Fri.-Fri. On-line workshop: Practical Rasch Measurement - Core Topics (E. Smith, Winsteps), www.statistics.com

 

 

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