Wh. Chen et D. Thissen, LOCAL DEPENDENCE INDEXES FOR ITEM PAIRS - USING ITEM RESPONSE THEORY, Journal of educational and behavioral statistics, 22(3), 1997, pp. 265-289
Citations number
16
Categorie Soggetti
Social Sciences, Mathematical Methods","Education & Educational Research
Four statistics are proposed for the detection of local dependence (LD
) among items analyzed using item response theory Among them, the X-2
and G(2) LD indexes are of special interest. Simulated data are used t
o study the distribution and sensitivity of these statistics under the
null condition, as well as under conditions in which LD is introduced
. The results show that under the null condition of local independence
, bath the X-2 and GZ LD indexes have distributions very similar to th
e chi(2) distribution with I degree of freedom. Under the locally depe
ndent conditions, both indexes appear to be sensitive in detecting LD
or multidimensionality among items. When compared to Q(3), another sta
tistic often used to detect LD, these new statistics are somewhat less
powerful for underlying LD, equally powerful for surface LD, and bett
er behaved in the null case.