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A Theory for the Measurement of Internet Information Retrieval

Description: The purpose of this study was to develop and evaluate a measurement model for Internet information retrieval strategy performance evaluation whose theoretical basis is a modification of the classical measurement model embodied in the Cranfield studies and their progeny. Though not the first, the Cranfield studies were the most influential of the early evaluation experiments. The general problem with this model was and continues to be the subjectivity of the concept of relevance. In cyberspace, information scientists are using quantitative measurement models for evaluating information retrieval performance that are based on the Cranfield model. This research modified this model by incorporating enduser relevance judgment rather than using objective relevance judgments, and by adopting a fundamental unit of measure developed for the cyberspace of Internet information retrieval rather than using recall and precision-type measures. The proposed measure, the Content-bearing Click (CBC) Ratio, was developed as a quantitative measure reflecting the performance of an Internet IR strategy. Since the hypertext "click" is common to many Internet IR strategies, it was chosen as the fundamental unit of measure rather than the "document." The CBC Ratio is a ratio of hypertext click counts that can be viewed as a false drop measure that determines the average number of irrelevant content-bearing clicks that an enduser check before retrieving relevant information. After measurement data were collected, they were used to evaluate the reliability of several methods for aggregating relevance judgments. After reliability coefficients were calculated, measurement model was used to compare web catalog and web database performance in an experimental setting. Conclusions were the reached concerning the reliability of the proposed measurement model and its ability to measure Internet IR performance, as well as implications for clinical use of the Internet and for future research in Information Science.
Date: May 1999
Creator: MacCall, Steven Leonard
Partner: UNT Libraries

Women Receiving Genetic Counseling for Breast Cancer Risk: Cancer Worry, Psychological Distress, and Risk Recall Accuracy

Description: This follows an earlier study of the same data set, which, through its findings, presented new questions that are investigated in this study. Both studies used a prospective controlled design, wherein women receiving genetic counseling for breast cancer risk were randomized into two groups. Subjects receiving an audiotaped recording of their genetic consultation (tape group) were compared to subjects who also had a genetic consultation but did not receive an audiotaped recording of it (no-tape group). Participants were drawn from attendees at the genetic clinics of two London hospitals and included 115 women with a family history of breast cancer. Cancer worry and psychological distress were assessed before genetic consultation (baseline), and at one- and six-month follow-ups by post. Objective risk was estimated by the geneticist during the consultation, and subjective risk was assessed at one month follow-up. The goals of the current study were to investigate relationships between cancer worry, psychological distress, and recall of genetic risk for breast cancer in a sample of women receiving genetic counseling for breast cancer risk, and to investigate the role sociodemographic variables on cancer worry, psychological distress, or risk recall for these women. Results for this sample of women with a family history of breast cancer found that there were consistent relationships between cancer worry, psychological distress, objective risk, and subjective risk before and after genetic consultation. This suggests that women=s psychological responses are appropriate to their level of cancer risk. There were no differences found between the tape and no-tape groups for objective or subjective risk, or for nearness of recall accuracy or degree of under-/over-estimation. Provision of an audiotaped recording of the genetic consultation did not appear to enhance recall of risk information. The role of sociodemographic variables on the psychological and risk variables assessed in this study was very ...
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Date: May 1999
Creator: Wade Walsh, Margo
Partner: UNT Libraries

A Different Drummer: A Chamber Opera

Description: A Different Drummer is a chamber opera adaptation of Donald Davis's story "A Different Drummer" from his collection Listening for the Crack of Dawn, published by August House. The opera lasts about seventy minutes, and calls for a cast of three and an orchestra of sixteen players. It contains a prologue, epilogue and four scenes in a single act. The score is prefaced by a paper describing the musical strategies employed in setting the story as an opera. Three chapters describe the adaptation from short story to opera, the essential musical elements, and details of the application of the musical elements in each scene of the opera. The libretto is presented in the fourth chapter.
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Date: May 1999
Creator: Friedman, Arnold Jacob
Partner: UNT Libraries

Current and Future Trends in Computer Use in Elementary School Settings

Description: The study examined current and future trends in computer use in elementary school settings. A survey instrument was developed and validated for distribution to a random sample of 200 technology coordinators in the public school districts in the state of Texas from whom 95 responses were received. The survey instrument was used to obtain information about five areas of computer use in elementary schools. These areas are: physical configurations, instructional uses, implementation issues, training and staff development, and Internet use. The study found that all public school districts that participated in the study have acquired computer hardware in their elementary schools. In addition, some other advanced computer technology components are starting to be found in elementary schools, such as teacher workstations, CD-ROM, interactive video, computer multimedia, LCD panels, and laser printers. Respondents reported that elementary school teachers in their districts have incorporated computers into their classrooms as an instructional tool and many changes have occurred in teachers’ teaching styles due to computers. However, there are some problems that hinder the effective use of computers. The major problem is lack of training. A high percentage of respondents, 81.3%, indicated that the majority of their elementary school teachers had completed less than 30 hours of technology related professional development. Another problem was lack of funding which prevents most school districts from acquiring computer hardware and software. Currently, elementary schools in 87% of districts that participated in the study are connected to the Internet and the plan is that by the year 2001 all elementary schools will be connected.
Date: August 1999
Creator: Al-Awidi, Hamed M.
Partner: UNT Libraries

Affective Reactions and Psychosocial Functioning in the Course of Psycho-Educational Assessment

Description: Every day, children throughout the United States are given psychological evaluations for many different clinical and psycho-educational purposes. Very little research has attempted to investigate children's responses to the experience of having intellectual and achievement tests administered. The goal of the current research was to explore the effect a psycho-educational evaluation has on children in areas of self-concept and anxiety. Dependent variables consisted of pre- and post-test measures of anxiety and self-concept. A total of 75 children in the 4th 5th and 6th grades were recruited after referral for evaluation and possible placement in the Talented and Gifted Program or Special Education. This study employed Analysis of Variance (ANOVA), t-tests, multiple regression analysis, and correlational analysis. Findings included initial evidence that children endorsed decreased anxiety after psycho-educational assessments rather than increased anxiety, suggesting that fear of unknown situations may be more anxiety provoking than the actual situation itself, potentially beneficial findings for psychology and psychometric professionals who evaluate children daily. Students endorsement of academic self-concept significantly predicted anxiety after a psycho-educational evaluation, indicating that students who feel capable in academic areas may endorse less anxiety after an evaluation than students who do not feel academically capable. Finally, negative verbal interaction with parents significantly predicted lower general self-concept scores, providing evidence that the manner in which parents verbally relate to their children may have significant impact for the mental health of children.
Date: August 1999
Creator: Buenrostro, Martha
Partner: UNT Libraries

Work Function Study of Iridium Oxide and Molybdenum Using UPS and Simultaneous Fowler-Nordheim I-V Plots with Field Emission Energy Distributions

Description: The characterization of work functions and field emission stability for molybdenum and iridium oxide coatings was examined. Single emission tips and flat samples of molybdenum and iridium oxide were prepared for characterization. The flat samples were characterized using X-ray Photoelectron Spectroscopy and X-ray diffraction to determine elemental composition, chemical shift, and crystal structure. Flat coatings of iridium oxide were also scanned by Atomic Force Microscopy to examine topography. Work functions were characterized by Ultraviolet Photoelectron Spectroscopy from the flat samples and by Field Emission Electron Distributions from the field emission tips. Field emission characterization was conducted in a custom build analytical chamber capable of measuring Field Emission Electron Distribution and Fowler-Nordheim I-V plots simultaneously to independently evaluate geometric and work function changes. Scanning Electron Microscope pictures were taken of the emission tips before and after field emission characterization to confirm geometric changes. Measurement of emission stability and work functions were the emphasis of this research. In addition, use of iridium oxide coatings to enhance emission stability was evaluated. Molybdenum and iridium oxide, IrO2, were characterized and found to have a work function of 4.6 eV and 4.2 eV by both characterization techniques, with the molybdenum value in agreement with previous research. The analytic chamber used in the field emission analysis demonstrated the ability to independently determine the value and changes in work function and emitter geometry by simultaneous measurement of the Field Emission Energy Distribution and Fowler-Nordheim I-V plots from single emitters. Iridium oxide coating was found to enhance the stability of molybdenum emission tips with a relatively low work function of 4.2 eV and inhibited the formation of high work function molybdenum oxides. However, the method of deposition of iridium and annealing in oxygen to form iridium oxide on molybdenum emitters left rather severe cracking in the protective oxide ...
Date: August 1999
Creator: Bernhard, John Michael
Partner: UNT Libraries

Information Seeking in a Virtual Learning Environment

Description: Duplicating a time series study done by Kuhlthau and associates in 1989, this study examines the applicability of the Information Search Process (ISP) Model in the context of a virtual learning environment. This study confirms that students given an information seeking task in a virtual learning environment do exhibit the stages indicated by the ISP Model. The six-phase ISP Model is shown to be valid for describing the different stages of cognitive, affective, and physical tasks individuals progress through when facing a situation where they must search for information to complete an academic task in a virtual learning environment. The findings in this study further indicate there is no relationship between the amount of computer experience subjects possess and demonstrating the patterns of thoughts, feelings, and actions described by the ISP Model. The study demonstrates the ISP Model to be independent of the original physical library environments where the model was developed. An attempt is made to represent the ISP model in a slightly different manner that provides more of the sense of motion and interaction among the components of thoughts, feelings, and action than is currently provided for in the model. The study suggests that the development of non-self-reporting data collection techniques would be useful in complementing and furthering research to enhance and refine the representation of the ISP Model. Additionally, expanding the research to include the examination of group interaction is called for to enhance the ISP Model and develop further applications that could potentially aid educational delivery in all types of learning environments.
Date: August 1999
Creator: Byron, Suzanne M.
Partner: UNT Libraries

A Structural Equation Model of Contributing Factors to Adolescent Social Interest

Description: The focus of the present study was to test through SEM the relationships between family influences (FI) and school influences (SI) on factors hypothesized to be associated with adolescent social interest: school belonging (SB), extracurricular participation (EP), and peer/romantic involvement (PRI). The final model consisted of FI and SI that contributed to the expression of adolescent social interest. FI included parental communication and parental caring. SI consisted of teacher fairness. SB consisted of a child's self-reported feelings of belonging at school, EP included self-reported involvement in sports or academic clubs, and PRI consisted of self-reported desire for romantic involvement or desire for participation with others. The proposed model suggested that FI contributed significantly to self-reported SB, EP, and PRI. Additionally, it was hypothesized that SI would contribute significantly to SB and EP, but not to PRI. The data used in the current study were part of an existing data set collected as part of the National Longitudinal Study on Adolescent Health. The total sample size for the present study was 2,561 male and female adolescents aged 12-19 years. The data consisted of adolescent and parent self-report information. Results suggested a significant relationship between FI and self-reported SB and PRI. As expected, a significant relationship existed between SI and SB. Also as expected, no significant relationship existed between SI and PRI. Neither the relationship between FI and EP nor SI and EP were significant. When analyzed separately, a significant relationship existed between SB and PRI; however, no significant relationship was found between SB and EP. Results also indicated several of the fit indices, including the average off-diagonal absolute standardized residual, the comparative fit index (CFI), and the Bentler-Bonett non-normed fit index (BBNFI), were a low to moderate fit. However, the final model was highly skewed and the model chi-square and chi-square ...
Date: August 1999
Creator: Craig, Stephen E.
Partner: UNT Libraries

Customer Induced Uncertainty and Its Impact on Organizational Design

Description: How firms facing environmental uncertainty should organize their activities remains an important and challenging question for today's managers and organizational researchers. Proponents of contingency theory have argued that organizations must adjust their activities to fit the level of environmental uncertainty to ensure long-term survival. Although much work has been done on contingency theory, it is clear that our understanding of uncertainty is far from complete. One important aspect of today's organizations is their focus on service, mass customization, and continuous innovation. This focus often results in the customer being brought either into the organization or at least into closer contact with it. Even though the literature provides numerous evidences of the increasing customer focus, it is yet to empirically explain how the complications of customer-organizational interactions might create uncertainty for contemporary organizations. The traditional measure of uncertainty still considers customers as an environmental factor causing demand uncertainty while ignoring the complex nature of customer and organizational encounters. Seeking to further refine the concept of uncertainty and focusing on the contemporary business phenomena, this study develops measures aspects of customer induced uncertainty and examines their relationships with three organizational design variables. Specifically, this study explains the complicated nature of customer - organizational encounters that creates organizational uncertainty. Also, this study develops three operational measurement instruments for the three aspects of customer induced uncertainty. Finally, this study shows specific relationships between aspects of customer induced uncertainty and specific organizational design variables. This study conducted a mail survey of middle level managers. With a sample size of 118 the measurement instruments were shown to have validity and reliability using factor analysis and Cronbach's alpha. Regression analyses indicate the presence of specific rather than general relationship between customer induced uncertainty variables and organizational design variables. Regression results suggested that the relationships between customer induced ...
Date: August 1999
Creator: Chowdhury, Sanjib Kumar
Partner: UNT Libraries

Profile of the Youth Self-Report Among South Texas Adolescents and the Potential Relationship to Pesticide Exposure

Description: The potential for human exposure to pesticides exists particularly for agricultural workers (i.e. migrant workers) and individuals within close proximity to pesticide-sprayed crops (i.e. those living on or near agricultural farms). Children, through biology and behavior, may be more susceptible and vulnerable to exposure to pesticides than adults. The purpose of this study was to examine young populations particularly at-risk for occupational or accidental exposure to pesticides and determine associated behavioral, emotional, and physical symptoms. A total of 444 students from two South Texas school districts completed questionnaires assessing level of risk of exposure to pesticides and were categorized into at-risk and low risk categories. Physical, emotional, and behavioral symptoms were obtained using the Youth Self-Report. Children who were at-risk demonstrated significantly higher scores on the Youth Self-Report (YSR) in the areas of anxious/depressed, attention problems, social problems, somatic complaints, thought problems, withdrawal, internalizing behaviors, and total problem behaviors than children who were at lower risk of pesticide exposure. Odds ratios were obtained and suggested that children in the at-risk category were more five times more likely to score in the clinically significant range on the Attention Problems subscale, and three times more likely to score in the clinically significant range on the Internalizing behavior composite. These findings suggest that children who may be at higher risk for pesticide exposure may also be at higher risk for physical, behavioral, and emotional problems compared to children who are at lower risk. This information is intended to benefit schools and health care professionals who work with rural or migrant populations involved in the agricultural trade. Future research will be needed to assess through biomarkers the degree of measurable pesticide exposure in comparison to parent reports, teacher reports, school achievement, neuropsychological testing, and medical records.
Date: August 1999
Creator: Hagar, Kristy S.
Partner: UNT Libraries

Night of No Exile

Description: Night of no Exile is a collection of poems preceded by a critical article entitled "‘Exile seems both a blessing and a curse': A Blissful Reading of Li-Young Lee's Poetry." That article discusses Lee's quest to achieve communication, truth, and transcendence through poetic language and concludes that he finally reaches his goal through a leap from narrative poetry to lyricism. The "exile" alluded to in the title of the article is not only geographic, but also interioran exile due to the natural limitations of all languages, and which can be bridged only in linguistic ways. Lee's solution to that problem (lyricism) turns his poetry into what Roland Barthes would call "a text of bliss," a text that manages to deeply destabilize language, while simultaneously achieving a new kind of meaning. In the main body of the manuscript, the first section contains short love lyrics. The second section, "Night of no Exile," is an attempt at the demanding genre of the longer lyric poem. The third section uses short lyrics to explore various topics, such as discovering one's identity, friendship and solidarity between women, family history, and childhood memories. Finally, the last section includes poems, four of them longer, attempting to combine narrative and lyric impulses in a way not unlike Li-Young Lee's experimentation with those two genres.
Date: August 1999
Creator: Jones, Marie C.
Partner: UNT Libraries

Explorations with Polycarbocyclic Cage Compounds

Description: A variety of novel cage-functionalized pyridyl containing crown ethers have been prepared for use in selective alkali metal complexation studies. A highly preorganized, cage-functionalized cryptand also has been designed and has been synthesized for use as a selective Li+ complexant. The alkali metal picrate extraction profiles of these cage-functionalized crown ethers also have been studied. Novel cage-functionalized diazacrown ethers have been prepared for selective alkali metal complexation studies. Alkali metal picrate extraction experiments have been performed by using this new class of synthetic ionophores to investigate the effects of cage-annulation and the influence of N-pivot lariat sidearms upon their resulting complexation properties. Novel pyridyl containing calix[4]arene receptors were prepared. Analysis of their respective 1H NMR and 13C NMR spectra suggests that calix[4]arene moieties in the ligand occupy the cone conformation. The complexation properties of these host molecules were estimated by performing a series of alkali metal picrate extraction experiments. An optically active cage-functionalized crown ether which contains a binaphthyl moiety as the chiral unit was prepared. The ability of the resulting optically active crown ether to distinguish between enantiomers of guest ammonium ions (i.e., phenylethylamonium and phenylglycinate salts) in transport experiments was investigated. Hexacyclo[11.2.1.02,12.05,10.05,15.010,14]hexadeca-6,8-diene-4,11-dione was prepared from hexacyclo[7.4.2.01,9.03,7.04,14.06,15] pentadeca-10,12-diene-2,8-dione. Unanticipated but remarkable acid and base promoted rearrangements of this new cage dione to novel polycyclic systems were observed and subsequently were investigated. The structures of the new systems thereby obtained were determined unequivocally by application of X-ray crystallographic methods. It is noteworthy that the reactions reported herein each provide the corresponding rearranged product in high yield in a single synthetic step. Pi-facial and regioselectivity in the thermal Diels-Alder cycloaddition between hexacyclo[11.2.1.02,12.05,10.05,15.010,14]hexadeca-6,8-diene- 4,11-dione and ethyl propiolate have been explored. This reaction proceeds via stereospecific approach of the dienophile toward the syn face of the diene p -system. However, [4+2]cycloaddition proceeds with ...
Date: August 1999
Creator: Chong, Hyun-Soon
Partner: UNT Libraries

A Study of Block Scheduling and Instructional Strategies and their Influence on Algebra Achievement in Classrooms Throughout North Central Texas

Description: The purpose of this study was to evaluate the influence of block scheduling and instructional strategies on student achievement in Algebra I. The study was conducted during the 1997-98 school year. This study was comprised of two components, a quantitative study and a qualitative study. The quantitative study focused on block and traditional scheduling and the influence identified through scores on the Texas End-of-Course exam for Algebra I. The sample for this study consisted of 59 school districts from five counties in the north Texas area. The qualitative portion of this study focused on 10 classrooms, 5 block and 5 traditional, taken from the sample of 59 districts. Data for the qualitative study included questionnaires, interviews, and observations. The End-of-Course scores were analyzed using an ANOVA at the .05 level of significance, no significant difference was identified in the achievement levels of the two groups. The qualitative data was organized by categories derived from the NCTM teaching standards. Data from this portion of the study indicated that teachers in both block and traditionally scheduled classes spend their class time in a similar manner, using similar materials, and using more traditional strategies. Additional analyses of data based upon usage of the graphing calculator and manipulatives also resulted in no significant difference. Although all comparisons between block and traditional scheduling and usage or non-usage of technology and/or manipulatives resulted in no significant difference, the block groups and those using technology and/or manipulatives had higher mean scores. This indicates that allowing teachers more time to use alternative instructional strategies would benefit the student, but this will not take place without the teacher receiving training and support.
Date: August 1999
Creator: McClure, Melissa Sue
Partner: UNT Libraries

A Discrimination of Software Implementation Success Criteria

Description: Software implementation projects struggle with the delicate balance of low cost, on-time delivery and quality. The methodologies and processes used to create and maintain a quality software system are expensive to deploy and result in long development cycle-time. However, without their deployment into the software implementation life-cycle, a software system will be undependable, unsuccessful. The purpose of this research is to identify a succinct set of software implementation success criteria and assess the key independent constructs, activities, carried out to ensure a successful implementation project. The research will assess the success of a software implementation project as the dependent construct of interest and use the software process model (methodology) as the independent construct. This field research involved three phases: (1) criteria development, (2) data collection, and (3) testing of hypotheses and discriminant analysis. The first phase resulted in the development of the measurement instruments for the independent and dependent constructs. The measurement instrument for the independent construct was representative of the criteria from highly regarded software implementation process models and methodologies, e.g., ISO9000, Software Engineering Institute's Capability Maturity Model (SEI CMM). The dependent construct was developed from the categories and criteria from the Delone and McLean (1992) MIS List of Success Measures. The data collection and assessment phase employed a field survey research strategy to 80 companies involved in internal software implementation. Both successful and unsuccessful software implementation projects (identified by the Delone/McLean model) participated. Results from 165 projects were collected, 28 unsuccessful and 137 successful. The third phase used ANOVA to test the first 11 hypotheses and employed discriminant analysis for the 12th hypothesis to identify the "best set" of variables, criteria, that discriminate between successful and unsuccessful software implementation projects. Twelve discriminating variables out of 67 were identified and supported as significant discriminators between successful and unsuccessful projects. ...
Date: August 1999
Creator: Pryor, Alan N.
Partner: UNT Libraries

The Computation of Ultrapowers by Supercompactness Measures

Description: The results from this dissertation are a computation of ultrapowers by supercompactness measures and concepts related to such measures. The second chapter gives an overview of the basic ideas required to carry out the computations. Included are preliminary ideas connected to measures, and the supercompactness measures. Order type results are also considered in this chapter. In chapter III we give an alternate characterization of 2 using the notion of iterated ordinal measures. Basic facts related to this characterization are also considered here. The remaining chapters are devoted to finding bounds fwith arguments taking place both inside and outside the ultrapowers. Conditions related to the upper bound are given in chapter VI.
Date: August 1999
Creator: Smith, John C.
Partner: UNT Libraries

Picosecond Dynamics of Free-Carrier Populations, Space-Charge Fields, and Photorefractive Nonlinearities in Zincblende Semiconductors

Description: Generally, nonlinear optics studies investigate optically-induced changes in refraction or absorption, and their application to spectroscopy or device fabrication. The photorefractive effect is a nonlinear optical effect that occurs in solids, where transport of an optically-induced free-carrier population results in an internal space-charge field, which produces an index change via the linear electrooptic effect. The photorefractive effect has been widely studied for a variety of materials and device applications, mainly because it allows large index changes to be generated with laser beams having only a few milliwatts of average power.Compound semiconductors are important photorefractive materials because they offer a near-infrared optical response, and because their carrier transport properties allow the index change to be generated quickly and efficiently. While many researchers have attempted to measure the fundamental temporal dynamics of the photorefractive effect in semiconductors using continuous-wave, nanosecond- and picosecond-pulsed laser beams, these investigations have been unsuccessful. However, studies with this goal are of clear relevance because they provide information about the fundamental physical processes that produce this effect, as well as the material's speed and efficiency limitations for device applications.In this dissertation, for the first time, we time-resolve the temporal dynamics of the photorefractive nonlinearities in two zincblende semiconductors, semi-insulating GaAs and undoped CdTe. While CdTe offers a lattice-match to the infrared material HgxCd1-xTe, semi-insulating GaAs has been widely used in optoelectronic and high-speed electronic applications. We use a novel transient-grating experimental method that allows picosecond temporal resolution and high sensitivity. Our results provide a clear and detailed picture of the picosecond photorefractive response of both materials, showing nonlinearities due to hot-carrier transport and the Dember space-charge field, and a long-lived nonlinearity that is due to the EL2 midgap species in GaAs. We numerically model our experimental results using a general set of equations that describe nonlinear diffraction and ...
Date: August 1999
Creator: Stark, Thomas S.
Partner: UNT Libraries

Academic Lineage and Student Performance in Medical School

Description: This research investigated the association between academic lineage and student performance in medical school. The purposes of the study were to: (1) determine whether the Carnegie classifications of medical school applicants' institutions of origin are associated with academic performance in medical school; (2) consider the relationship between the admission selectivity of the schools of origin and the academic performance of medical school students; (3) compare the performance of medical students from institutions under public governing control with students from privately controlled institutions; and (4) establish a model by which the relative academic strengths of applicants from a variety of undergraduate institutions can be understood more clearly based on the previous performance of medical students from schools with similar institutional characteristics. A review of the literature on medical school admissions was completed and used to develop this research. Medical students from the University of Texas Southwestern Medical Center at Dallas who enrolled between the years 1990 and 1994 and graduated or were dismissed between the years 1994 and 1998 were selected as the sample for the study (n=933). The undergraduate institution of origin for each student was coded based on its Carnegie classification, admissions selectivity group, and whether its governing control was public or private. Because the sample was not randomly selected and the data likely would not meet the assumptions of equal means and variance with the population, nonparametric analyses of variance and multiple comparison tests were completed to compare the groups of the independent variables over each dependent variable. The analyses revealed that for the sample of medical students selected for this study there was an association between academic lineage and student performance in medical school. Differences were found among Carnegie classifications on the dependent variables of cumulative medical school grade point average, class rank, failure rate, and score ...
Date: August 1999
Creator: Wright, James Scott
Partner: UNT Libraries

An Assessment of the Use of Seeding, Mowing, and Burning in the Restoration of an Oldfield to Tallgrass Prairie in Lewisville, Texas

Description: An examination of the effectiveness of seeding, burning, and mowing in the reestablishment of tallgrass prairie species on overgrazed and abandoned pastureland. The study site is a 20 acre tract on U.S. Corps of Engineers land below Lake Lewisville in Denton County, Texas. The site was partitioned into thirty-nine 40 by 40 meter plots with seeding (carried out in 1996) and management treatment (burning, mowing, and no maintenance carried out in 1998) randomly applied following a two level design. For each plot, nine stratified-random 0.1 m2 subplots were examined and shoot counts for each species recorded. The effects of the treatments on individual species and species richness were analyzed with a two-way ANOVA followed by a SNK multiple range test, both on ranked data. Community level analysis was conducted with both a MANOVA on ranked data and a Canonical Correspondence Analysis on raw data. Results indicate that seeding positively affected species richness, particularly when combined with either burning or mowing in the early spring. Mowing also significantly increased species richness in areas that were not seeded, while burning negatively affected species richness on unseeded plots. Treatments significantly affected community composition with treatments having the most clear effect on spring and summer forbs.
Date: August 1999
Creator: Windhager, Steven
Partner: UNT Libraries

The Effect of Increased Collaboration Among the Library Media Specialist and School Personnel on Perceptions of the Roles and Responsibilities of the Library Media Specialist

Description: This study measured and explored changes in perceptions of the roles and responsibilities of the library media specialist when the level of collaboration increased. Seven library media specialists targeted four members of their educational communities with whom to increase collaborative activities. Before and after the collaboration began, the library media specialists, the teachers with whom they chose to collaborate, other members from the same educational community, and a control group that did not participate in increased collaboration were given a roles and responsibilities rank-order form. This form was used to measure changes in perceptions regarding the importance of the three roles and selected responsibilities related to the three roles before and after the collaborative experience. The library media specialists and the targeted teachers also kept reflection logs to record factors that enhanced collaboration, factors that inhibited collaboration, and any changes in their teaching style as a result of the collaborative experience. Results indicate that the participating library media specialists themselves experienced the most change. Role identification remains a problem as library media specialists seek to become teaching partners with classroom teachers yet still must keep the library media center aligned with school and district goals and move toward making it an information center that provides information resources for all members of the educational community in an effective, efficient and timely manner. Major enhancers to increased collaboration included flexible scheduling of the library, sharing ideas and resources, partnership in teaching, and student achievement. Major inhibitors included time, wanting to keep things the way they were, and lack of resources. Changes in teaching practice included working with another professional instead of in isolation, integrating many resources into the lesson to provide for the learning needs of all students, the incorporation of technology into the lesson, and an awareness of the roles of ...
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Date: August 1999
Creator: Beaird, Marilyn Miller
Partner: UNT Libraries

Development of Cardiovascular Regulation in Embryos of the Domestic Fowl (Gallus Gallus), with a Partial Comparison to Embryos of the Desert Tortoise (Gopherus Agassizii)

Description: In adult vertebrates, cardiovascular regulation is accomplished by numerous systems with neural, hormonal and local components responsible for the majority of regulation. These regulatory components work in concert to maintain the essential function of blood perfusion to adult tissues. Given the essential nature of this function it is therefore surprising that the development of cardiovascular regulation during gestation is poorly understood. The majority of what is known is based on a single vertebrate model, the fetal lamb. The fetal lamb has been used in multiple studies due to the clear clinical applications and has been pivotal in understanding the onset of regulation in developing vertebrates. However, study on the fetal lamb is limited to the latter 40% of gestation and has the added complication of an in-utero developmental strategy. Therefore the primary focus of this dissertation was to characterize basic cardiovascular regulation in the chicken embryo to provided the needed information for it's use an alternative to the fetal lamb. Developing chicken embryos rely on both alpha and beta adrenergic tones to maintain normal heart rate and arterial blood pressure during incubation. However, on day 21, just prior to hatch, these animals lose both tones on arterial pressure suggesting the onset of adult regulation. Cholinergic tone, however, was absent throughout chicken development indicating that it must mature during the neonatal life. Adult cardiovascular reflexes become apparent late in chicken development with a clear baroreflex specifically operating initially on day. However, an adult response to changes in ambient gas tension was absent during incubation suggesting embryos possess unique regulatory systems that are absent in adult chickens. This mechanism is comprised entirely of adrenergic systems with no cholinergic action during change in ambient gas tension. Similar developmental patterns were determined in embryos of the desert tortoise suggesting fundamental differences between in-utero and ...
Date: August 1999
Creator: Crossley, Dane Alan
Partner: UNT Libraries

Animals-as-Trope in the Selected Fiction of Zora Neale Hurston, Alice Walker, and Toni Morrison

Description: In this dissertation, I show how 20th century African-American women writers such as Zora Neale Hurston, Alice Walker, and Toni Morrison utilize animals-as-trope in order to illustrate the writers' humanity and literary vision. In the texts that I have selected, I have found that animals-as-trope functions in two important ways: the first function of animal as trope is a pragmatic one, which serves to express the humanity of African Americans; and the second function of animal tropes in African-American women's fiction is relational and expresses these writers' "ethic of caring" that stems from their folk and womanist world view. Found primarily in slave narratives and in domestic fiction of the 19th and early 20th centuries, pragmatic animal metaphors and/or similes provide direct analogies between the treatment of African-Americans and animals. Here, these writers often engage in rhetoric that challenges pro-slavery apologists, who attempted to disprove the humanity of African-Americans by portraying them as animals fit to be enslaved. Animals, therefore, become the metaphor of both the abolitionist and the slavery apologist for all that is not human. The second function of animals-as-trope in the fiction of African-American women writers goes beyond the pragmatic goal of proving African-Americans's common humanity, even though one could argue that this goal is still present in contemporary African-American fiction. Animals-as-trope also functions to express the African-American woman writer's understanding that 1) all oppressions stem from the same source; 2) that the division between nature/culture is a false onethat a universal connection exists between all living creatures; and 3) that an ethic of caring, or relational epistemology, can be extended to include non-human animals. Twentieth-century African-American writers such as Hurston, Walker, and Morrison participate in what anthropologists term, "neototemism," which is the contemporary view that humankind is part of nature, or a vision that Morrison would ...
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Date: August 1999
Creator: Erickson, Stacy M.
Partner: UNT Libraries

Developing Criteria for Extracting Principal Components and Assessing Multiple Significance Tests in Knowledge Discovery Applications

Description: With advances in computer technology, organizations are able to store large amounts of data in data warehouses. There are two fundamental issues researchers must address: the dimensionality of data and the interpretation of multiple statistical tests. The first issue addressed by this research is the determination of the number of components to retain in principal components analysis. This research establishes regression, asymptotic theory, and neural network approaches for estimating mean and 95th percentile eigenvalues for implementing Horn's parallel analysis procedure for retaining components. Certain methods perform better for specific combinations of sample size and numbers of variables. The adjusted normal order statistic estimator (ANOSE), an asymptotic procedure, performs the best overall. Future research is warranted on combining methods to increase accuracy. The second issue involves interpreting multiple statistical tests. This study uses simulation to show that Parker and Rothenberg's technique using a density function with a mixture of betas to model p-values is viable for p-values from central and non-central t distributions. The simulation study shows that final estimates obtained in the proposed mixture approach reliably estimate the true proportion of the distributions associated with the null and nonnull hypotheses. Modeling the density of p-values allows for better control of the true experimentwise error rate and is used to provide insight into grouping hypothesis tests for clustering purposes. Future research will expand the simulation to include p-values generated from additional distributions. The techniques presented are applied to data from Lake Texoma where the size of the database and the number of hypotheses of interest call for nontraditional data mining techniques. The issue is to determine if information technology can be used to monitor the chlorophyll levels in the lake as chloride is removed upstream. A relationship established between chlorophyll and the energy reflectance, which can be measured by satellites, enables ...
Date: August 1999
Creator: Keeling, Kellie Bliss
Partner: UNT Libraries

Peer Education: Building Community Through Playback Theatre Action Methods

Description: The primary purpose of this study was to use some of the action methods of playback theatre to facilitate the acquisition of knowledge through the experience of building community. The impact of action methods on group dynamics and the relationship among methods, individual perceptions, and the acquisition of knowledge were analyzed. The researcher suggested that playback theatre action methods provided a climate in which groups can improve the quality of their interactions. The Hill Interaction Matrix (HIM) formed the basis for the study's analysis of interactions. Since the researcher concluded there were significantly more interactions coded in the "power quadrant" after training, the researcher assumed that playback theatre action methods are a catalyst for keeping the focus on persons in the group, encouraging risk-taking behaviors, and producing constructive feedback between members. Based on session summaries, individual interviews, and an analysis of the Group Environment Scale (GES), the training group became more cohesive, became more expressive, promoted independence, encouraged self-discovery, and adapted in innovative ways. The experience of an interconnected community created a space where positive growth could occur. The researcher concluded that the process of community building is intricately connected with a person's ability to make meaning out of experiences. Participants in the study noted several processes by which they acquired new knowledge: (a) knowledge through internal processes, (b) knowledge through modeling, (c) knowledge through experiences, (d) knowledge through acknowledgment and application. Acknowledging and applying knowledge were behaviors identified as risk-taking, communication and active listening, acceptance of diverse cultures and opinions, and building community relations. The study suggested further research in the effects of these methods compared to other learning methods, the effects of these methods on other types of groups, the effects of the leader's relationship to the group, and the long-term effects on group dynamics.
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Date: August 1999
Creator: Kintigh, Monica R.
Partner: UNT Libraries