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Introduction

This document explains how to create constraints data forloadConstraints(). Automated test assembly in practice isoften desired to assemble a test so that its contents adhere to a testblueprint, which asserts various requirements the assembled test shouldsatisfy. As ofTestDesign version 1.1.0, constraints can beread in fromdata.frame objects or.csvspreadsheet files. The input data is expected to be in the followingstructure:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB
C1	Number	Item		30	30
C2	Number	Item	LEVEL == 3	10	10
C3	Number	Item	LEVEL == 4	10	10
C4	Number	Item	LEVEL == 5	10	10
C5	Number	Item	STANDARD == 1	17	20

Constraints data must have seven columns, named asCONSTRAINT_ID,TYPE,WHAT,CONDITION,LB,UB,ONOFF on the first row. Beginning from the second row, eachrow must have corresponding values for each column. A convenient way forworking with constraints is to use a spreadsheet application(e.g. Excel) and work on the content from there.

Readers are also encouraged to tinker with example constraintsincluded in the package:

constraints_science_data (all discrete items)
constraints_reading_data (set-based blueprint)
constraints_fatigue_data (uses enemy items)
constraints_bayes_data (uses word countconstraints)

Required columns

Column 1: CONSTRAINT_ID

This column specifies the identifier of each constraint. Charactervalues can be used as long as the values are unique.

Column 2: TYPE

This column specifies the type of constraint. Following values areexpected:Number,Order,Enemy,Include,Exclude,AllorNone.

Number specifies the constraint to be applied to thenumber of selected items (ifWHAT column isItem), or to the number of selected item sets (ifWHAT column isStimulus). For example, thefollowing row tells the solver to select a total of 30 items.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C1	Number	Item		30	30

Sum specifies the constraint to be applied to the sumof attributes of selected items (ifWHAT column isItem), or of selected item sets (ifWHATcolumn isStimulus). For example, the following row tellsthe solver to keep the sum ofWORDS between 500–600.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C2	Sum	Item	WORDS	500	600

Order specifies the selection to be made in ascendingorder. The following row tells the solver to select the items inascendingLEVEL, based on supplied attributes.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C32	Order	Item	LEVEL

Enemy specifies the items (or item sets) matching thecondition to be treated as enemy items. To tell the solver to select atmost one of the two items:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C33	Enemy	Item	ID %in% c(“SC00001”, “SC00002”)

Include specifies the items matching the condition tobe always included in selection. For example, the following row tellsthe solver to include itemsSC00003 andSC00004:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C34	Include	Item	ID %in% c(“SC00003”, “SC00004”)

Exclude specifies the items matching the condition tobe always excluded from selection. The following row tells the solver toexclude items that matchPTBIS < 0.15, based on supplieditem attributes.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C35	Exclude	Item	PTBIS < 0.15

AllOrNone specifies the items matching the condition tobe either all included or all excluded. To tell the solver to eitherselect itemsSC00005 andSC00006 at the sametime or exclude them at the same time:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C36	AllOrNone	Item	ID %in% c(“SC00005”, “SC00006”)

Column 3: WHAT

This column specifies the unit of assembly the constraint uses.Expected values areItem orStimulus.

Column 4: CONDITION

This column specifies the condition of the constraint. An Rexpression returning logical values (TRUE orFALSE) is expected. The variables supplied in itemattributes can be used in the expression as variable names.

Some examples are:

"STANDARD %in% c(2, 4)" tells the solver to select whenSTANDARD is either 2 or 4.
"STANDARD %in% c(2, 4) & DOK >= 3" tells thesolver to select whenSTANDARD is either 2 or 4, and alsoDOK is at least 3.
!is.na(FACIT) tells the solver to select whenFACIT is not empty.
Leave it empty to not specify any condition. This is useful inconstraining the total number of items.

ForTYPE == SUM, using a variable name imposes theconstraint on the sum of the variable. The following row tells thesolver to keep the sum ofWORDS between 500–600.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C2	Sum	Item	WORDS	500	600

ForTYPE == SUM, constraints on conditional sums can beimposed by using a variable name, placing a comma, and then giving an Rexpression returning logical values. The following row tells the solverto keep the sum ofWORDS withinDOK == 1 itemsbetween 50–80.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C3	Sum	Item	WORDS, DOK == 1	50	80

In set-based assembly,Per Stimulus can be used tospecify the number of items to select in each stimulus. For example, thefollowing row tells the solver to select 4 to 6 items per stimulus:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C3	Number	Item	Per Stimulus	4	6

Column 5-6: LB and UB

These two columns specify lower and upper bounds on the number ofselected items. These must be specified whenTYPE isNumber, and otherwise must be left empty.

Some example rows are provided.

To select a total of 12 items:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C1	Number	Item		12	12

To select 15 to 30 items satisfyingDOK >= 2:

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C17	Number	Item	DOK >= 2	15	30

Column 7: ONOFF

Set this toOFF to turn off the constraint from beingapplied.ON or leaving it blank applies the constraint. Thefollowing example specifies the order constraint to be not applied.

CONSTRAINT_ID	TYPE	WHAT	CONDITION	LB	UB	ONOFF
C18	Order	Passage	CONTENT			OFF

Movatterモバイル変換

Creating constraints in TestDesignpackage

Sangdon Lim