Thesis (Ph. D.)--John Hopkins University, 1933. / Vita. Includes bibliographical references (p. 43-46).

Doctor of Philosophy / Department of Statistics / John E. Boyer Jr., Dallas E. Johnson / A crossover design is an experimental design in which each experimental unit receives a series of experimental treatments over time. The order that an experimental unit receives its treatments is called a sequence (example, the sequence AB means that treatment A is given first, and then followed by treatment B). A period is the time interval during which a treatment is administered to the experimental unit. A period could range from a few minutes to several months depending on the study. Sequences usually involve subjects receiving a different treatment in each successive period. However, treatments may occur more than once in any sequence (example, ABAB). Treatments and periods are compared within subjects, i.e. each subject serves as his/her own control. Therefore, any effect that is related to subject differences is removed from treatment and period comparisons. Carryover effects are residual effects from a previous treatment manifesting themselves in subsequent periods. Crossover designs both with and without carryover are traditionally analyzed assuming that the response due to different treatments have equal variances. The effects of unequal variances on traditional tests for treatment and carryover difference were recently considered in crossover designs assuming that the response due to treatments have unequal variances with a compound symmetry correlation structure. The likelihood function for the two treatment/two sequence crossover design has closed form maximum likelihood solutions for the parameters at both the null hypothesis, H0 : sigma_A^2 =\sigma_B^2, and at alternative hypothesis, HA : not H0. Under HA : not H0, the method of moment estimators and the maximum likelihood estimators of sigma_A^2,sigma_B^2 and rho are identical. The dual balanced design, ABA=BAB, which is balanced for carryover effects is also considered. The dual balanced design has a closed form solution that maximizes the likelihood function under the null hypothesis, H0 :sigma_A^2=sigma_B^2, but not for the alternative hypothesis, HA : not H0. Similarly, the three treatment/three sequence crossover design, ABC=BCA=CAB, has a closed form solution that maximizes the likelihood function at the null hypothesis, H0 : sigma_A^2=sigma_B^2 = sigma_C^2, but not for the alternative hypothesis, HA : not H0. An iterative procedure is introduced to estimate the parameters for the two and three treatment crossover designs. To check the performance of the likelihood ratio tests, Type I error rates and power comparisons are explored using simulations.

The Basic Competency Test for Junior High School Students (BCT) has become the most important and the largest test, which is including the most number of students, the widest range and the largest number of printed paper. The BCT has deeply influenced the benefits whether three hundred thousand students are able to enter their ideal senior high schools or not. Moreover, the BCT has also become the big issue of education which all people are concerned about. The study is according to the massive questionnaire to students in the third grade of public and private junior high schools in Taiwan, their parents, students in the first grade of senior / vocational high schools, and the related educators. The main findings of the study were as follows: 1. Generally speaking, though students, parents and educators have a few different views of most identified items of BCT, the quality of the items is still highly affirmative while its function and purpose are questioned. 2. The attitude of students, parents and educators to BCT exists the evidently great differences. 3. Students who come from different backgrounds have obviously different attitude to BCT. 4. Parents from different backgrounds have obviously different attitude to BCT. 5. Educators from different backgrounds have obviously different attitude to BCT. 6. The studies of students in the third grade of junior high school is obviously influenced by BCT. 7. The BCT has caused pressure and problem to students, parents and educators. 8. The BCT does not reach the expected function. 9. The places, dates, and whether to announce the range of BCT are not accorded with the demands of the public. 10. Students, parents and educators have different demands on BCT. 11. The so-called ¡§ two peaks ¡¨ are presented to the satisfactions for students, parents and educators on BCT. According to the findings, the study provides some suggestions to the actual implement of BCT and the further study.

The purpose of this investigation was to examine the construct validity of a new test, which purports to measure morphology, entitled Test for Examining Expressive Morphology (TEEM) (Shipley, Stone and Sue, 1983). Additional tests of expressive morphology, the Bankson Language Screening Test (BLST) (Bankson, 1977) and the Test of Language Development-Primary (TOLD-P) (Newcomer and Hammill, 1982) were utilized to determine the association of the TEEM with two highly-researched instruments.

This study dealt with the problem of investigating the validity of two recently developed paper-and-penci1 tests of programmer aptitude , the Aptitude Test for Programmer Personnel (ATPP) and the Computer Programmer Aptitude Battery (CPAB), in predicting success in computer programming.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1990. / Includes bibliographical references (leaves 138-151) / Microfiche. / ix, 151 leaves, bound 29 cm

Doctor of Philosophy / Department of Statistics / Haiyan Wang / Various tests have been created to compare the means of two populations in many scenarios and applications. The two-sample t-test, Wilcoxon Rank-Sum Test and bootstrap-t test are commonly used methods. However, methods for skewed two-sample data set are not well studied. In this dissertation, several existing two sample tests were evaluated and four new tests were proposed to improve the test accuracy under moderate sample size and high population skewness. The proposed work starts with derivation of a first order Edgeworth expansion for the test statistic of the two sample t-test. Using this result, new two-sample tests based on Cornish Fisher expansion (TCF tests) were created for both cases of common variance and unequal variances. These tests can account for population skewness and give more accurate test results. We also developed three new tests based on three transformations (T[subscript i] test, i = 1; 2; 3) for the pooled case, which can be used to eliminate the skewness of the studentized statistic. In this dissertation, some theoretical properties of the newly proposed tests are presented. In particular, we derived the order of type I error rate accuracy of the pooled two-sample t-test based on normal approximation (TN test), the TCF and T[subscript i] tests. We proved that these tests give the same theoretical type I error rate under skewness. In addition, we derived the power function of the TCF and TN tests as a function of the population parameters. We also provided the detailed conditions under which the theoretical power of the two-sample TCF test is higher than the two-sample TN test. Results from extensive simulation studies and real data analysis were also presented in this dissertation. The empirical results further confirm our theoretical results. Comparing with commonly used two-sample parametric and nonparametric tests, our new tests (TCF and Ti) provide the same empirical type I error rate but higher power.

I dagens digitala samhälle är tester på applikationer och kodbaser ett vanligt förekommande fenomen. Tester utförs på flera företag både manuellt och automatiskt och vill gärna rekrytera personer med kunskap inom testning. Mittuniversitetet i Sundsvall har ännu inga kurser för testning men det skulle vara passande för studenter att bli introducerade till detta redan tidigt när de läser ett program. Syftet med denna studie har varit att identifiera ett passande ramverk för kurser om testning på universitet. För att kunna genomföra studien utfördes en kvalitativ litteraturstudie om testning. Sedan valdes två stycken ramverk anpassade för enhetstestning utifrån en kravspecifikation. De utvalda ramverken var JUnit 5 och TestNG. Ramverken testades utifrån dess användbarhet, funktionalitet och effektivitet genom att köra tester mot en befintlig chattapplikation. Vidare utfördes användartest för att undersöka ramverkens lämplighet för användning under en universitetskurs där målgruppen hade olika erfarenheter och datorvana. Resultatet visade på att JUnit 5 var bättre när det kom till användning, dokumentation och lämplighet för en kurs på universitet. Rekommendationen är att JUnit 5 passar till att använda i en kurs på universitet. Det rekommenderas också att universitet bör introducera kurser med testning så att studenten naturligt implementerar ett iterativt förhållningssätt till programmering samt blir mer förberedd inför arbetslivet. / In today’s digital society, testing of applications and code bases is a common phenomenon. Testing are performed on several companies, both manually and automatically, and would like to recruit people with knowledge about testing. Mid Sweden University in Sundsvall does not yet have courses about testing but it would be appropriate for students to be introduced to this early on while they study a program. The purpose with this study has been to identify a suitable framework for university courses about testing. In order to be able to carry out the study, a qualitative literature study on testing was performed to gather information. Furthermore two framework were selected that was adapted for unit testing and based on a requirements specification. The chosen frameworks were JUnit 5 and TestNG. The frameworks were tested based on their usability, functionality and efficiency by running tests against an existing chat application. Furthermore, user tests were performed to examine the suitability of the frameworks for use during a university course where the target group have different experiences and computer skills. The result showed that JUnit 5 was better when it came to usability, documentation and suitability for a course at a university. The recommendation is that JUnit 5 is suitable for a course at a university. It’s also recommended that the university should introduce courses with testing so that the student naturally implements an iterative approach to programming and become more prepared for working with programming and development.

Saudi Arabia has been trying to change its long tradition of relying on fossil fuels and seek renewable energy sources such as wind power. In this thesis, I firstly provide a comprehensive assessment of wind energy resources and associated spatio-temporal patterns over Saudi Arabia in both current and future climate conditions, based on a Regional Climate Model output. A high wind energy potential exists and is likely to persist at least until 2050 over a vast area ofWestern Saudi Arabia, particularly in the region between Medina and the Red Sea coast and during Summer months. Since an accurate assessment of wind extremes is crucial for risk management purposes, I then present the first high-resolution risk assessment of wind extremes over Saudi Arabia. Under the Bayesian framework, I measure the uncertainty of return levels and produce risk maps of wind extremes, which show that locations in the South of Saudi Arabia and near the Red Sea and the Persian Gulf are at very high risk of disruption of wind turbine operations. In order to perform spatial predictions of the bivariate wind random field for efficient turbine control, I propose parametric variogram matrix (function) models for cokriging, which have the advantage of allowing for a smooth transition between a joint second-order and intrinsically stationary vector random field. Under Gaussianity, the covariance function is central to spatio-temporal modeling, which is useful to understand the dynamics of winds in space and time. I review the various space-time covariance structures and models, some of which are visualized with animations, and associated tests. I also discuss inference issues and a case study based on a high-resolution wind-speed dataset. The Gaussian assumption commonly made in statistics needs to be validated, and I show that tests for independently and identically distributed data cannot be used directly for spatial data. I then propose a new multivariate test for spatial data by accounting for the spatial dependence. The new test is easy to compute, has a chi-square null distribution, and has a good control of the type I error and a high empirical power.

This study was designed to determine whether varying criterion for pass/fail on the Mini-Screening Language Test for Adolescents (Mini-STAL) would increase accuracy of predicting outcome of the Screening Test of Adolescent Language (STAL). The Mini-STAL was developed by Prather et al. (1981) to identify rapidly those students between grades six through twelve who are in need of language intervention. Using Prather's established criterion (one or more errors equal failure), the Phoenix school district (Prather, 1981) found too many of their school population (20 percent) were failing the Mini- STAL. Thus, they established an experimental criterion (two or more errors equal failure) to identify those students with language problems. The present study sought to determine what proportion of students with language disorders was not detected by the Mini-STAL and what proportion of students without language disorders failed the Mini-STAL using the two criteria.