PSELECT= person selection criterion

Persons to be selected may be specified by using the PSELECT= instruction to match characters within the person name. Persons deleted by PDFILE= etc. are never selected by PSELECT=.

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.

Persons to be selected may be specified by using the PSELECT= instruction to match characters within the person name. Persons deleted by PDFILE= etc. are never selected by PSELECT=.

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.
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 person records which match A or B or X

Each PSELECT= 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 +PSELECT=

Example 1: Select for analysis only persons with M in the 5th column of person name. Person name starts in column 6 of the data record:

NAME1=6 Person name field starts in col. 6

NAMLEN=8 Person name field is 8 characters long

PSELECT=????M* Column 5 of person name is sex

END NAMES

xxxxxBPL M J 01101000101001 selected

xxxxxMEL F S 01001000111100 omitted

-----1234 selection column

Example 2: Select for analysis all persons with code "A 4" in columns 2-4 of their names. Person name starts in column 23, so target characters starts in column 24:

NAME1=23 person name starts in column 23

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

selects ZA 4PQRS

Example 3: Select all Male (M in column 2) persons who are Asian or Hispanic (A or H in column 4):

PSELECT=?M?{AH}*

selects 1M3A456 MPQRS

selects 1M5H689 ABCDE

omits 1X2A123 QWERT

Example 4: Select Males (M in column 8) in School 23 (023 in column 14-16):

PSELECT= ???????M?????023*

Selects: 1234567MABCDE023XYZ

Example 5: Select codes 1,2,3,4,5,6,7, in column 2:

PSELECT=?{1-7}*

Example 6: Analyze only males (column 4 or person-id). Then report only School C (column 1). Then only report Grades 4 and 5 (column 2) in School C.

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

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

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

Example 7: There are 100000 examinees from 17 school districts in one data file. I want to process only 16 districts.

If the district code is one character, then you can select the 16 codes you want, for instance:

If the codes are letters in column 4 of the person label

PSELECT=???{ABDEFGHIJKLMNOPQR}

PSELECT=???{~C} ; omits unwanted school district C

Example 8: 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 person label. Look at a data record to see what is actually there.

PSELECT=???????????????23 ; selects "23" in columns 16 and 17

Example 9: Item statistics are needed for each person classification.

If you want PSELECT= to alter the item statistics, then please do separate Winsteps analyses for each PSELECT= value. Place the PSELECT= in your control file, or enter it at the "Extra Specifications (if any)" prompt. This PSELECT= will change what is shown for the persons and the items.

If you want to keep the item difficulties, person abilities and rating scale structure from the complete analysis, rather than re-estimating them. Then
Complete analysis -> PFILE=pf.txt, IFILE=if.txt, SFILE=sf.txt,
PAFILE=pf.txt, IAFILE=if.txt, SAFILE=sf.txt, PSELECT= -> selected analysis.

The "Specification" pull-down menu alter what is included in directly-relevant output tables.
So, entering PSELECT= at the "Specification" pull-down menu will change what is shown in the person tables, but not what is shown in the item tables.