Considered normative from the second half of the 20th century (Danziger, 1990), null hypothesis statistical testing (NHST) has received consistent, largely unheeded criticism. Critiques have received more attention in recent years with the recognition of the replication crisis in the social sciences and the American Statistical Society's statement…

Measurement invariance is crucial for an effective and valid measure of a construct. Invariance holds when the latent trait varies consistently across subgroups; in other words, the mean differences among subgroups are only due to true latent ability differences. Differential item functioning (DIF) occurs when measurement invariance is violated.…

When researchers fit statistical models to multiply imputed datasets, they have to fit the model separately for each imputed dataset. Since there are multiple datasets, there are always multiple sets of model results. It is possible for some of these sets of results not to converge while some do converge. This study examined occurrence of such a…

In education, sample characteristics can be complex due to the nested structure of students, teachers, classrooms, schools, and districts. In the past, not many considerations were given to such complex sampling schemes in statistical power analysis. More recently in the past two decades, however, education scholars have developed tools to conduct…

Cloud computing offers the advantage of on-demand, reliable and cost efficient computing solutions without the capital investment and management resources to build and maintain in-house data centers and network infrastructures. Scalability of cloud solutions enable consumers to upgrade or downsize their services as needed. In a cloud environment,…

Propensity score analysis has been used to minimize the selection bias in observational studies to identify causal relationships. A propensity score is an estimate of an individual's probability of being placed in a treatment group given a set of covariates. Propensity score analysis aims to use the estimate to create balanced groups, akin to a…

Information technology (IT) investment decision makers are required to process large volumes of complex data. An existing body of knowledge relevant to IT portfolio management (PfM), decision analysis, visual comprehension of large volumes of information, and IT investment decision making suggest Multi-Criteria Decision Making (MCDM) and…

The Burr families (Type III and Type XII) of distributions are traditionally used in the context of statistical modeling and for simulating non-normal distributions with moment-based parameters (e.g., Skew and Kurtosis). In educational and psychological studies, the Burr families of distributions can be used to simulate extremely asymmetrical and…

This dissertation addresses the broad question about how phonology and phonetics are interrelated, specifically how phonetic language changes, which gradually alter the phonetics of speech sounds, affect the phonological system of the language, and vice versa. Some questions I address are: (i) What aspects of speakers' knowledge of their language…

"It is often assumed that changing the classroom by introducing technology will result in better teaching and increased student motivation, which ultimately means more effective student learning experiences" (Donovan, Green, & Hartley, 2010, p. 423). But does it? This is the controversy and debate that surrounds the promise and…

Often researchers face situations where comparative studies between two or more programs are necessary to make causal inferences for informed policy decision-making. Experimental designs employing randomization provide the strongest evidence for causal inferences. However, many pragmatic and ethical challenges may preclude the use of randomized…

The present study compared the performance of five missing data treatment methods within a Cross-Classified Random Effects Model environment under various levels and patterns of missing data given a specified sample size. Prior research has shown the varying effect of missing data treatment options within the context of numerous statistical…

This dissertation uses quantitative and geographic analysis techniques to examine the historical and geographical processes that have shaped California's linguistic diversity. Many questions in California historical linguistics have received diminishing attention in recent years, remaining unanswered despite their continued relevance. The studies…

This dissertation reports the results of three studies and a pilot study. The first study was a Monte Carlo validation study that examined the accuracy of a new visual inspection method, the semi-interquartile range method. Results of the study indicated that this method had lower levels of power than a previously validated method, the…

Hierarchical Linear Modeling (HLM) sample size recommendations are mostly made with traditional group-design research in mind, as HLM as been used almost exclusively in group-design studies. Single-case research can benefit from utilizing hierarchical linear growth modeling, but sample size recommendations for growth modeling with HLM are scarce…