Technical Report - International Military Testing Association

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To fllurtratr how the indexor of validity for aach itaa lcflucoca
the validity of the tote1 tart, consider tho follcwin~~ formlo,
Ubrt4:
ber thb validity of the
‘xv tart,
Zri,ot, the itma validity lndasi;,
io tha point-bioerlal itemcriterion
currolatioo
multiplied by tho itrar
rtmdrrd deviation,
Bitei, ths itaP roltebility
index, io the pointbioerial
ItCE-tQot
correlation luultipliod
by ths itom otmdard
doviotfon.
Prom one cf our validity � ������ #the volfdfry eoefflcieot for tha
tot81 test was .52. It wao found that the Cricoi two equal to 5.541,
and Eritoi wab equal to 10.5’77. Entering the above equotlon YO find:
‘w -
5.551
10.577
Solving for the above, the rtV oqualo .525 which corraopondo to the .52
which woo the volldity of th’o totol evaluation teat cmputod ftm the
Powron product-nt formula. uoe of the indu of validity ptanotoo
the � oundneoo of the “item-b,ank” concept,vhstetn numtouD prwfourly
tried Itmoo pro readily wcsooible to the toot conotructor.
Another urrful placr of information that vi11 bo provided thr teat
� pmialloto lo a grophlc plot of the itaa-validity indexer and the itwe
reliability indoxeo for each of the icmaa. One CM, thrroforo, tall at
a glance vhich itano are contributing moot to teat validfty and taut
reliability. Thio lo eooentlally tho oome kind of graphic dzrtration
ahown by cu~likmn $n hio chapter on itm � olyoio.
Row there ore the major changer in our volidotion � tudioo which vo
bavr preomtly incorporated. Since Incorporating thio nmthcd, we have
cuoplated or aeorly completed studier on � pproximtely oevon different
mllitmy occupational opoci*litioo. Portunotoly, nearly all of rho teoto
evaluated no far poorsrr � oam drgrar of aapirical validity.
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52
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