Understanding the characteristics of research participants is crucial to ensuring sample representativeness and generalizability of findings to broader patient groups with substance use disorders. Using anonymous computer-administered health survey data, the present study had a unique opportunity to compare patients who chose to participate in an RCT for heavy/problem drinking or drug use (N=713; consenters) with those that chose not to participate (N=625; non-consenters). The sample was 40% male, 76% African American, and had a mean age of 45.2 years. Using multivariate regression, the most parsimonious model found older age, unemployment, prescription misuse, positive screen for drug problems (CAGE), having a grandmother with an alcohol problem, trouble falling asleep (past 30 days), health professional recommendation to go on a diet, and feeling unsafe due to a previous partner were all associated with consenting to participate. The present study provides benchmark data on sample representativeness in a clinical trial of SBIRT.

This study investigated the extent to which rules proposed by Tong and Brennan (2007) for estimating standard errors of estimated variance components held up across a variety of G theory designs, variance component structures, sample size patterns, and data types. Simulated data was generated for all combinations of conditions, and point estimates, standard error estimates, and coverage for three types of confidence intervals were calculated for each estimated variance component and relative and absolute error variance across a variety of bootstrap procedures for each combination of conditions. It was found that, with some exceptions, Tong and Brennan's (2007) rules produced adequate standard error estimates for normal and polytomous data, while some of the results differed for dichotomous data. Additionally, some refinements to the rules were suggested with respect to nested designs. This study provides support for the use of bootstrap procedures for estimating standard errors of estimated variance components when data are not normally distributed.

High-stakes testing is used for the purposes of providing results that have important consequences such as certifications, licensing, or credentialing. The purpose of this study was to examine aspects of an exam recently written by flight paramedics for recertification and make recommendations for development of future exams. In 2008, an unexpectedly high failure led to revisions in the exam development process for flight paramedics. Using principles of classical test theory and generalizability theory, I examined the decision consistency and dependability of the examination and found the decision consistency for dichotomous items to be within acceptable limits, yet the dependability was low. Discrimination was strong at the cut-score. An in-depth look into the process used to set the exam, as well as the psychometric properties of the exam and the items have led to recommendations that will contribute to future development of dependable exams in the industry that result in more valid interpretations with respect to paramedic competence. / Thesis (Master, Education) -- Queen's University, 2012-09-06 22:41:41.552

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abstract: Science is a formalized method for acquiring information about the world. In recent years, the ability of science to do so has been scrutinized. Attempts to reproduce findings in diverse fields demonstrate that many results are unreliable and do not generalize across contexts. In response to these concerns, many proposals for reform have emerged. Although promising, such reforms have not addressed all aspects of scientific practice. In the social sciences, two such aspects are the diversity of study participants and incentive structures. Most efforts to improve scientific practice focus on replicability, but sidestep issues of generalizability. And while researchers have speculated about the effects of incentive structures, there is little systematic study of these hypotheses. This dissertation takes one step towards filling these gaps. Chapter 1 presents a cross-cultural study of social discounting – the purportedly fundamental human tendency to sacrifice more for socially-close individuals – conducted among three diverse populations (U.S., rural Indonesia, rural Bangladesh). This study finds no independent effect of social distance on generosity among Indonesian and Bangladeshi participants, providing evidence against the hypothesis that social discounting is universal. It also illustrates the importance of studying diverse human populations for developing generalizable theories of human nature. Chapter 2 presents a laboratory experiment with undergraduates to test the effect of incentive structures on research accuracy, in an instantiation of the scientific process where the key decision is how much data to collect before submitting one’s findings. The results demonstrate that rewarding novel findings causes respondents to make guesses with less information, thereby reducing their accuracy. Chapter 3 presents an evolutionary agent-based model that tests the effect of competition for novel findings on the sample size of studies that researchers conduct. This model demonstrates that competition for novelty causes the cultural evolution of research with smaller sample sizes and lower statistical power. However, increasing the startup costs to conducting single studies can reduce the negative effects of competition, as can rewarding publication of secondary findings. These combined chapters provide evidence that aspects of current scientific practice may be detrimental to the reliability and generalizability of research and point to potential solutions. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2018

<p>Religious faith has been identified as a protective factor against negative psychological outcomes and is associated with a range of positive mental and physical health outcomes. While religion is thought to confer psychological benefits to believers in part by enhancing emotion regulation abilities and providing faith-based regulatory methods such as religious coping, these associations have not been examined empirically. This may be due to a lack of measures that are appropriate for use in repeated measures contexts, which are needed for accurate assessment of dynamic constructs such as emotions and regulation. This study employed generalizability theory in a sample (N = 146) collected in daily dairy format over 21 days to determine the reliability of commonly used measures of religiosity and religious coping at the daily level. Once reliability was established, varying time scales were used in a multilevel modeling framework to examine the associations among intrinsic religiosity, religious coping, positive and negative affect, and difficulties in emotion regulation. Positive religious coping (PRC) measured at baseline, same day, and a 1-day lag was associated with higher levels of daily positive affect, though PRC was also associated with negative affect when measured on the same day. Negative religious coping (NRC) measured at baseline predicted lower levels of daily positive affect and was associated with higher levels of negative affect when measured on the same day and a 1-day lag. NRC was also associated with higher levels of difficulties in emotion regulation at all measurement periods, though PRC and intrinsic religiosity were not significantly associated with emotion regulation difficulties. While not associated with daily positive or negative affect, intrinsic religiosity was found to enhance the effect of positive affect inertia. These results did not support the conceptualization that religiosity broadly promotes adaptive emotion regulation, but rather that intrinsic religiosity may increase positive affect by amplifying the effects of positive affect inertia. Additional work is needed with increased measurement occasions to fully understand the temporal associations among these constructs.</p>

This present study examined the application of generalizability theory (GT) to the Parenting Stress Index (PSI) long and short forms for families having children with disabilities. The purpose of the study was to evaluate the dependability of parenting stress data scores gathered from families having children with disabilities. The data for the present study came from an extant data set collected by the Early Intervention Research Institute (EIRI; Contract #800-85-0173) at Utah State University. The EIRI studies represented attempts to assess the benefits and cost of conducting early intervention programs. The EIRI data were recoded at the item level for the Psychometrics Project, which established norms, reliability, and validity information on self-report, family-functioning measures gathered from families having children with disabilities. The GT study results suggested that the items facet made a large contribution, indicating that there may not be any established trends in item responses. An explanation for the items facet indicates that the PSI forms provide an accurate measure of overall parental stress. According to the times facet results, the effects of time are minimal except the increase between occasion one to occasion two. Classical reliability theory (CRT) and GT analyses provide contradictory results, probably due to GT's multiple error source analyses compared to CRT's examination of a single error source in one analysis. GT study analyses indicate that the highest g and phi coefficients are produced with the highest number of administrations and items. However, administering the highest number of administrations and items would be impractical within any setting. The original number of items from the Parent Domain, Child Domain, and short PSI total score should be administered twice to increase the dependability of scores and still fall within practical limitations. A researcher and/or practitioner may want information to decide what form, long or short, to choose. If the PSI is to be used as a quick screening tool or as one test in a complete assessment, the short form may be of more use. If the PSI is to be used as a primary source of information about parent and child interactive systems, the long PSI version would be recommended.

The purpose of this study was to investigate three different programs designed to increase verbal and physical sharing and to determine the generalizability and durability of the behaviors that were trained. Eight groups of four preschool children, balanced for sex, were observed for 16 minutes daily during a free play period in their preschool classroom. After eight days of baseline, 24 children received one of three types of training for eight sessions. Eight children were taught to verbally share, eight to physically share, and eight to both verbally and physically share. All of these children received a treatment package composed of instructions, modeling, behavioral rehearsal, prompting, and praise. After the training phase, these children were returned to the baseline condition for eight days. The remaining eight children served as a no treatment control. Each day immediately following free play the children were observed for 12 minutes while working on a different task (art) in a different classroom, with a different experimenter, observers, and materials. Four weeks after training ended all the children were observed for an additional five days during both the free play and art activities. Children trained to verbally share showed an increase in verbal sharing which diminished when treatment was withdrawn and failed to generalize to another setting (art). There was, however, a concomitant increase in physical sharing during both activities that was maintained even during the follow-up. Similarly, children taught to share verbally and physically demonstrated the same effects of treatment as those receiving only training in verbal sharing. The magnitude of these effects, however, was slightly greater for those children who were taught both types of sharing. Training in only physical sharing produced larger increases in physical sharing in both settings than the other two approaches but these effects were lost when treatment was terminated. Verbal sharing among these children was unaffected by the treatment. Finally, for those children who did not receive any training, no systematic increases in either verbal or physical sharing were observed. Therefore, the high level of physical sharing during the follow-up for those children who were only taught to verbally share and for those who were instructed to verbally and physically share was not due to the change in the natural course of sharing over time but rather due to the treatments. Training children to verbally share, physically share, or both had no effect on the rate with which they refused to share. The present findings suggest that to facilitate sharing among preschool children, at a minimum they must be taught to share verbally. Training children to share only physically is not recommended because it was not durable and did not generalize. Training both verbal and physical sharing produced results with a magnitude slightly greater than teaching just verbal sharing but in the absence of a cost-benefit analysis, the additional training is questionable. Without special programming some of the effects generalized to another setting and were maintained about four weeks after the termination of the treatment. There was response generalization of verbal to physical sharing but not vice versa. Hypotheses concerning why generalization occurred without specific programming, future areas of research, and ethical considerations are discussed.

The air that humans exhale contains various chemical markers whose levels have been associated with various respiratory disorders. Therefore, measurement of these markers offers a potential method of examining airway disease status. Furthermore, exhaled breath offers the advantage of being easy to collect and non-invasive. Hence, these exhaled breath markers are potentially of significant clinical use in examining airways. Therefore, examination of exhaled breath has become the subject of intense study. Current research is targeting the development of methods and parameters for looking at these markers. The goal of this cross-sectional pilot study was to consider the variability in the measurement of these exhaled breath markers between members of different ethnic populations. Specifically, measurements of the exhaled breath marker Nitric Oxide (NO) were compared between two ethnic groups (Caucasian men versus men of African descent). Ten healthy men in each group were studied to examine whether baseline NO measurements differed between them. In this study, a cross-sectional design was used. The study sample consisted of young, healthy men with no history of environmental allergies, asthma, or lung diseases and no significant smoking history. A total of twenty-five men volunteered for the study, including fourteen men of Caucasian descent and eleven men of African descent. Because four men were excluded and one withdrew, ten men in each ethnic group were included in the final analysis. The source population from which the sample was drawn included students and workers. All participants were residing in Florida at the time of study. Ideally, the target population for this study was young, healthy, working men. Large inter-measurement variation was seen between the participants of each ethnic group. This was hypothesized to be attributed to a tri-modal distribution due to the existence of 3 populations of subjects: (1) asymptomatic with normal airways, where NO levels were under 30 parts per billion (ppb); (2) asymptomatic with airway pathology, where NO levels were over 30 ppb; and (3) asymptomatic just before the onset of an upper respiratory tract infection, where NO levels were over 60 ppb. This pilot study did not find statistically significant evidence that there is a difference in the baseline exhaled breath NO measurements between the two ethnic groups studied. Nonetheless, in participants with NO levels under 30 ppb the mean of the African group was found to be 7.6 ppb lower than the mean of the Caucasian group when attempts were made to exclude individuals with underlying airway pathology or imminent upper respiratory tract infection. In order to find statistical significance in the results, a power analysis using the standard deviation of 7.7 ppb that was found in this study indicates that at least thirty-two eligible participants with NO levels under 30 ppb would be required. Only 13 such participants were examined in this study, Thus, at least fifty eligible participants would be required to find significant results. The implication is that even though statistical significance was not achieved, the crude mean averages differed between the two groups in participants with NO levels under 30 ppb. This implies that a larger-scale well-designed study is warranted before NO is used in clinical settings in the diagnosis and monitoring of patients.

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