Assessing students' emerging literacy skills is crucial for identifying areas where a child may be falling behind and can lead directly to an increased chance of reading success. The Waterford Assessment of Core Skills (WACS), a computerized adaptive test of early literacy for students in prekindergarten through 2nd grade, addresses this need.…

Empirical information regarding performance of model-fit procedures has been a persistent need in measurement practice. Statistical procedures for evaluating item fit were applied to real test examples that consist of both dichotomously and polytomously scored items. The item fit statistics used in this study included the PARSCALE's G[squared],…

This report provides a description of the development process, field testing, and psychometric properties of a student mathematics test designed to assess grades 1 and 2 student abilities. The test was administered to 2,373 participating grade 1 and 2 students in 22 schools located in 2 public school districts in Florida during fall 2013. Focused…

Composite scores are often formed from test scores on educational achievement test batteries to provide a single index of achievement over two or more content areas or two or more item types on that test. Composite scores are subject to measurement error, and as with scores on individual tests, the amount of error variability typically depends on…

"Scaling" is the process of constructing a score scale that associates numbers or other ordered indicators with the performance of examinees. Scaling typically is conducted to aid users in interpreting test results. This module describes different types of raw scores and scale scores, illustrates how to incorporate various sources of…

A Markov chain Monte Carlo (MCMC) method and a bootstrap method were compared in the estimation of standard errors of item response theory (IRT) true score equating. Three test form relationships were examined: parallel, tau-equivalent, and congeneric. Data were simulated based on Reading Comprehension and Vocabulary tests of the Iowa Tests of…

ACT college test publisher provided scores. On average, non-homeschoolers performed better than homeschoolers, by about two items, out of sixty items, on the ACT mathematics test that was analyzed. This result may be due to the different teaching/learning media used in teaching each of the two groups, to different teacher/student interaction, or…

Compared performance of two polytomous item response theory models to that of the dichotomous three-parameter logistic model in equating tests composed of testlets using data from 6 tests of the Iowa Tests of Basic Skills (samples of 537 to 680 eighth graders). Results of the equating method based on polytomous models produced results that more…

Four equating methods were compared using four equating criteria: first-order equity (FOE), second-order equity (SOE), conditional mean squared error (CMSE) difference, and the equipercentile equating property. The four methods were: (1) three parameter logistic (3PL) model true score equating; (2) 3PL observed score equating; (3) beta 4 true…

Previous research has shown that testlet structures often violate important assumptions of dichotomous item response theory (D-IRT) models, applied to item-level scores, that can in turn affect the results of many measurement applications. In this situation, polytomous IRT (P-IRT) models, applied to testlet-level scores, have been used as an…

The performance of three equating methods--the presmoothed equipercentile method, the item response theory (IRT) true score method, and the IRT observed score method--were examined based on three equating criteria: the same distributions property, the first-order equity property, and the second-order equity property. The magnitude of the…

The interaction of reading and computational abilities in solving mathematics word problems was investigated with the responses of about 20,000 fourth graders and 20,000 eighth graders to items from the Iowa Tests of Basic Skills. Item responses exhibited different types of interaction, a finding with implications for item-response theory…

The Level-11 vocabulary subtest of the Iowa Tests of Basic Skills was analyzed using a two-stage latent trait approach and data set of 2,356 examinees, approximately 11 years of age. It is concluded that the nonparametric approach leads to efficient estimation of the latent trait. (SLD)

Technical problems with norm-referenced achievement testing that can lead to the erroneous evaluation of schools for Chapter 1 Program improvement is discussed, and an alternative testing model is presented. The history of Chapter 1 testing and evaluation policies is briefly reviewed, and problems with the norm-referenced model are explored. Data…