ISELECT= item selection criterion

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.
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 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 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