This thesis reports the performance of a simple classifier as a function of its training data set. The classifier is used to remove analog tests and is named the Test Removal Classifier (TRC). The thesis proposes seven different training data set designs that vary by the number of wafers in the data set, the source of the wafers and the replacement scheme of the wafers. The training data set size ranges from a single wafer to a maximum of five wafers. Three of the training data sets include wafers from the Lot Under Test (LUT). The training wafers in the data set are either fixed across all lots, partially replaced by wafers from the new LUT or fully replaced by wafers from the new LUT. The TRC's training is based on rank correlation and selects a subset of tests that may be bypassed. After training, the TRC identifies the dies that bypass the selected tests. The TRC's performance is measured by the reduction in over-testing and the number of test escapes after testing is completed. The comparison of the different training data sets on the TRC's performance is evaluated using production data for a mixed-signal integrated circuit. The results show that the TRC's performance is controlled by a single parameter- the rank correlation threshold.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of North Carolina at Greensboro, 2006. / Title from PDF title page screen. Advisor: Richard Luecht; submitted to the School of Education. Includes bibliographical references (p. 89-94).

Not available / text

Not available / text

国立情報学研究所で電子化したコンテンツを使用している。

国立情報学研究所で電子化したコンテンツを使用している。

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 87-91).

The fallibility of human judgment in the making of decisions requires the use of tests to enhance decision-making processes. Although testing is surrounded with issues of bias and fairness, it remains the best means of facilitating decisions over more subjective alternatives. As a country in transition, all facets of South African society are being transformed. The changes taking place within the tertiary education system to redress the legacy of Apartheid, coincide with an international trend of transforming higher education. One important area that is being transformed relates to university entrance requirements and admissions procedures. In South Africa, these were traditionally based on matriculation performance, which has been found to be a more variable predictor of academic success for historically disadvantaged students. Alternative or revised admissions procedures have been implemented at universities throughout the country, in conjunction with academic development programmes. However, it is argued in this dissertation that a paradigm shift is necessary to conceptualise admissions and placement assessment in a developmentally oriented way. Furthermore, it is motivated that it is important to keep abreast of advances in theory, such as item response theory (IRT) and technology, such as computerized adaptive testing (CAT), in test development to enhance the effectiveness of selecting and placing learners in tertiary programmes. This study focuses on investigating the use of the Accuplacer Computerized Placement Tests (CPTs), an adaptive test battery that was developed in the USA, to facilitate unbiased and fair admissions, placement and development decisions in the transforming South African context. The battery has been implemented at a university in the Eastern Cape and its usefulness was investigated for 193 participants, divided into two groups of degree programmes, depending on whether or not admission to the degree required mathematics as a matriculation subject. Mathematics based degree programme learners (n = 125) wrote three and non-mathematics based degree programme learners (n = 68) wrote two tests of the Accuplacer test battery. Correlations were computed between the Accuplacer scores and matriculation performance, and between the Accuplacer scores, matriculation performance and academic results. All yielded significant positive relationships excepting for the one subtest of the Accuplacer with academic performance for the non-mathematics based degree group. Multiple correlations for both groups indicated that the Accuplacer scores and matriculation results contribute unique information about academic performance. Cluster analysis for both groups yielded three underlying patterns of performance in the data sets. An attempt was made to validate the cluster groups internally through a MANOVA and single-factor ANOVAs. It was found that Accuplacer subtests and matriculation results do discriminate to an extent among clusters of learners in both groups of degree programmes investigated. Clusters were described in terms of demographic information and it was determined that the factors of culture and home language and how they relate to cluster group membership need further investigation. The main suggestion flowing from these findings is that an attempt be made to confirm the results with a larger sample size and for different cultural and language groups.

The work reported in this dissertation investigates the potential for embedding Computerised Adaptive Testing (CAT) in students' and tutors' educational experiences. It seems that the tailored assessments that CAT can provide would be of real educational value in a range of contemporary Higher Education settings, however the resource requirements of some forms of CAT are prohibitive for making CAT assessments available to students across their studies. A form of CAT that is less resource intensive than other forms, the Flexilevel test, was selected for this programme of research to investigate its effectiveness in real educational contexts and explore possible applications for the approach. Ten empirical studies and a real data simulation study were conducted to test the effectiveness of the approach. It was found to show statistically significant correlations with other forms of assessment - in particular conventional Computer Based Testing (CBT) assessments, which is commonly used in contemporary educational settings. Another strand of work concerned the attitudes of stakeholders to the approach. Part of this work was carried out through the empirical studies, and further studies including interviews were also undertaken to explore the views of academic staff and students to the use of the Flexilevel test. Both groups were positive about the use of the Flexilevel test and this was taken to support the idea that academic staff and students would accept the use of the Flexilevel test in their educational experiences. In terms of both effectiveness and the acceptability of the approach to academic staff and students, the Flexilevel test was found to be a good candidate for embedding CAT in real educational contexts in Higher Education.