Enhancing the Equating of Item Difficulty Metrics: Estimation of Reference Distribution. Research Report. ETS RR-14-07

Autor/inn/en	Ali, Usama S.; Walker, Michael E.
Titel	Enhancing the Equating of Item Difficulty Metrics: Estimation of Reference Distribution. Research Report. ETS RR-14-07
Quelle	In: ETS Research Report Series, (2014), (8 Seiten)Infoseite zur Zeitschrift PDF als Volltext kostenfreie Datei Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	2330-8516
Schlagwörter	Difficulty Level; Test Items; Equated Scores; Causal Models; Item Response Theory; Statistical Distributions; Computation + Suchen Sie Ihr Suchwort? Schwierigkeitsgrad; Test content; Testaufgabe; Kausalanalyse; Item-Response-Theorie; Wahrscheinlichkeitsverteilung
Abstract	Two methods are currently in use at Educational Testing Service (ETS) for equating observed item difficulty statistics. The first method involves the linear equating of item statistics in an observed sample to reference statistics on the same items. The second method, or the item response curve (IRC) method, involves the summation of conditional observed item statistics across the reference population total score frequencies. This article introduces a quick and effective method for obtaining the reference distribution for the transition from the linear equating method to the IRC method without recalculating all the item difficulties. More specifically, a mathematical formula is derived to estimate the score distribution of a reference group that maintains the current item difficulty scale. Future research is needed to compare the performance of the two approaches. (As Provided).
Anmerkungen	Educational Testing Service. Rosedale Road, MS19-R Princeton, NJ 08541. Tel: 609-921-9000; Fax: 609-734-5410; e-mail: RDweb@ets.org; Web site: https://www.ets.org/research/policy_research_reports/ets
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01