Monday, February 25, 2013

Cumulative Tests

Educational testing has increased dramatically in recent years. Both the number of student assessments and the types of assessments provided for students have grown extensively. These changes have produced significant challenges for the testing industry and for schools implementing assessments. In the past, test development was a slow process controlled in the main by test developers. Today, rapid ongoing test development driven by continually changing educator needs is the norm. The result is an accumulation of tests comprised of many closely related assessments administered to many groups of students at many different times. 

The demands associated with the construction of high quality assessments in the current educational environment are significant. In many cases the number of students taking a test is too small to support adequate psychometric analyses. Test length is also a major issue. Tests that take longer than one class period to administer pose a scheduling challenge for schools. Yet, tests administered in one class period often do not provide the degree of measurement precision that can be obtained from a longer assessment. In addition, short tests typically provide only limited coverage of the underlying ability that the test is designed to measure. For some time now, ATI has been working on a new cumulative approach to test development, test scoring, test analysis, and test reporting. 

A cumulative test is typically thought of as test that covers the full range of content in a course of study. Aside from the range of content covered, a cumulative test is like any other test. That is, it is one test given to a group of examinees at one time. The cumulative construct being addressed by ATI expands the definition of a cumulative test. A Cumulative Test, as it is conceptualized in this is typically comprised of many tests, administered in many sessions to many groups of examinees on many occasions across an extended time period. A Cumulative Test is assumed to measure a single latent ability. However, sets of items on the test may also reflect specific factors in addition to that ability. In the limiting case, a Cumulative Test will include two tests administered in two sessions to two groups of examinees on two occasions. A given examinee can be expected to respond to some number of test items, but not all of the items comprising the test. To qualify as an examinee, an individual must respond to at least one item on the test.

The introduction of Cumulative Tests into educational assessment produces many potential benefits.  A Cumulative Test makes it possible to use all of the available data for parameter estimation. The responses of all students responding to a given item can be considered in estimating parameters for that item. Cumulative Tests provide an increasing amount of data as time passes. Thus, the precision of estimates of ability improves as students respond to an increasing number of items. A Cumulative Test provides massive amounts of information that can be used to guide instruction when a large number of items are included in the assessment. A Cumulative Test has the potential to improve forecasting accuracy because it facilitates the use of all of the available data in making the forecast.  Cumulative Tests support the measurement of growth from customized assessments aligned with district curricula because they provide extremely broad coverage of the knowledge and skills to be acquired through instruction. 

Given the many advantages of the cumulative assessment paradigm, it is reasonable to expect that the use of Cumulative Tests will expand in the years ahead. The availability of technology in schools is likely to play an important role in that expansion. As technology availability increases, assessments providing information to guide instruction can be expected to become an integral part of the instructional process. As this increase occurs, Cumulative Tests, which are designed to guide instruction, can be expected to take their place as a new and useful assessment tool uniquely positioned to serve changing educational needs that have emerged as the world has entered the information age. 

No comments: