992 resultados para longitudinal case study
Resumo:
This paper presents a case study to illustrate the range of decisions involved in designing a sampling strategy for a complex, longitudinal research study. It is based on experience from the Young Lives project and identifies the approaches used to sample children for longitudinal follow-up in four less developed countries (LDCs). The rationale for decisions made and the resulting benefits, and limitations, of the approaches adopted are discussed. Of particular importance is the choice of sampling approach to yield useful analysis; specific examples are presented of how this informed the design of the Young Lives sampling strategy.
Resumo:
Case study research has the advantage of investigating issues that are embedded within the context of the case. A novel approach to investigation of the implementation of service innovation process has been adopted through a longitudinal ethnographic case study. This approach was found useful, as the outcome of the study was intended to be an in-depth understanding of firm’s current innovation practices and its consequences with the implementation of a novel business process. In this applied research, an array of longitudinal data was generated chiefly through the technique of participant-observation. Participant-observation as a qualitative or naturalistic method has its roots in ethnographic research. Participant-observation involves “participating in the social world, in whatever role, and reflecting on the products of that participation” (Hammersley & Atkinson, 1983, p.16). This method offers a degree of understanding of the context under study that can come only from personal experience. In this presentation, I discuss the role of the researcher-practitioner as participant-observer and the usefulness of ethnographic case study methodology and participant-observation technique to investigating service innovation practices that are embedded within the context-specific setting of the case.
Resumo:
Red cell number and size increase during puberty, particularly in males. The aim of the present study was to determine whether expression of genes affecting red cell indices varied with age and sex. Haemoglobin, red cell count, and mean cellular volume were measured longitudinally on 578 pairs of twins at twelve, fourteen and sixteen years of age. Data were analysed using a structural equation modeling approach, in which a variety of univariate and longitudinal simplex models were fitted to the data. Significant heritability was demonstrated for all variables across all ages. The genes involved did not differ between the sexes, although there was evidence for sex limitation in the case of haemoglobin at age twelve. Longitudinal analyses indicated that new genes affecting red cell indices were expressed at different stages of puberty. Some of these genes affected the different red cell indices pleiotropically, while others had effects specific to one variable only.
Resumo:
In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.
Resumo:
INTRODUCTION AND HYPOTHESIS: The objective of this study is to assess anatomical and functional results of the extraperitoneal uterosacral ligament suspension (USL) in women with post-hysterectomy vaginal vault prolapse. METHODS: One hundred and twenty-three consecutive women were included. Concurrent procedures were anterior colporraphy with fascial repair (20%) and mesh reinforcement (49%), posterior colporraphy with fascial repair (38%) and mesh reinforcement (56%) and a sling procedure (29%). Women were assessed using Baden and Walker and pelvic organ prolapse quantification classification pre- and post-operatively. RESULTS: One hundred and ten patients (89%) were available for follow-up. Mean follow-up was 2 years. Objective success rate regarding the vaginal cuff is 95.4%. Global anatomical success rate was 85.5%. Urinary, coital and bowel symptoms were improved following surgery. Mesh exposure rate was 19.3%, with all cases managed conservatively or with minor interventions. CONCLUSION: Bilateral extraperitoneal USL is an effective operation to restore apical support with low morbidity, which avoids potential risks associated with opening the peritoneal cavity.
Resumo:
This study focuses on understanding the internationalisation of small and medium-sized enterprises (SMEs) from an emerging market to a developed market. In particular, it examines the internationalisation process of a firm in the clothing and textile manufacturing industry in Ghana. Theoretically, the study is limited to the network internationalisation approach (e.g. Johanson & Mattsson, 1988; Johanson & Vahlne, 2009) and the industrial network approach (Håkansson & Snehota, 1995). Methodologically, a qualitative abductive case study approach is employed. The research process relies on a longitudinal method involving primary and secondary data and critical event analysis. Primary data has been collected from relevant informants at two different times in the internationalisation process. The research findings highlight the significance of both domestic and foreign business relationships in the internationalisation of an SME from an emerging African market to a developed country market. They show the greater importance of exogenous critical events than has been found in the research regarding firms in developed countries. Institutional actors were essential in the network and as sources of exogenous critical events. In addition, the successful SME should possess unique resources in the form of an entrepreneurial spirit, sufficient knowledge of internationalisation, and specific product knowledge. Theoretically, the present study contributes to business network research through providing an understanding of the process of developing network relationships and their impact in an African context. By focusing on SMEs, a contribution has been made in relation to the advancement of SME research. This research reveals empirical insight into SME internationalisation in a setting where an SME is internationalising to a developed country market from a newly emerging African market. Methodologically, the study provides an example of longitudinal research based on abductive methodology. The results provide implications for firms, managers, and policy-makers within the industry, especially on how to manage and use network relationships to promote SME internationalisation from newly emerging markets.
Resumo:
Parent-child sexual health communication can be beneficial. Many factors affect such communication in Chinese immigrant families. This qualitative study explored the influences of acculturation, parenting, and parental participation in the Raising Sexually Healthy Children Program (RSHC) on such communication. With a hermeneutic framework, the purpose was to develop understanding based on the topic, context, and researcher interpretations. Twelve interviews elicited data from six parent-child dyads, three from the RSHC. Analysis involved coding processes; data were compared repeatedly and organized into themes. Perceived personality differences between generations were confounded with cultural communicative differences. Parents used implicitness observed in Chinese culture to establish "open" communication; children expected explicitness observed in Western culture. Post- RSHC, parents perceived themselves as more open to talking about sex; children did not perceive such parental changes. Future research should include joint interviews and longitudinal program evaluation. Future practice should focus on cross-cultural communication and involving children in RSHC.
Resumo:
Existing studies revealed several conflicts around the memory of the Holocaust in Poland: between understanding the need to teach about the Holocaust and indifference toward anti-Jewish graffiti; a conflict around the perception of Polish help to Jews; and the competing images of Polish and Jewish suffering during World War II. Those conflicts will be addressed in the paper as reflecting educational gaps in the Polish education system (lack of bad memory). This paper will look at the consciousness of young Poles, in terms of attitudes toward Jews, the Holocaust and memory of the Holocaust. The data presented are the preliminary results of the author’s longitudinal study „Attitudes of Young Poles toward the Jews and the Holocaust”. Quantitative and qualitative studies include field studies and participant observation of educational projects in Tykocin, Treblinka, Warsaw, Lublin, Bodzentyn and Kielce. The paper will present some components of the development of education about the Holocaust in Poland. There is a need to evaluate the attempt to bring back the memory of Jewish neighbours in some of the states of Central and Eastern Europe, a process with an ongoing effort to renovate monuments, destroyed cemeteries and synagogues. The number and scope of such initiatives in Poland indicate that civic institutions and individuals are intensifying their efforts to teach their fellow citizens about the Holocaust, however their impact should be assessed in detail.
Resumo:
Although the literature has provided many critiques of research done on family preservation programs, these critiques have usually been limited to the studies ' assumptions, approach, or methodology. Because of the nature of these critiques, suggestions for future research in this field of practice have been scattered throughout the literature and have not benefited from a wider historical perspective. This paper examines the historical evolution of family preservation studies in child welfare and suggests future directions for research in the field. Among the suggestions the authors posit are (1) research questions should be framed by what we know about improvements in the lives of families and children served by family preservation programs; (2) future explorations should include areas that have received relatively little attention in current research, including the impact of organizational conditions on service fidelity and worker performance; (3) newer treatment models, particularly those that provide both intensive services during a crisis period and less intensive services for maintenance, should be tested; (4) data collection points in longitudinal studies should be guided by theory, and measures should change over time to reflect the theoretically expected changes in families; (5) complex measures of placement prevention and other measures that capture changes in family functioning, child well-being, and child safety, should be utilized to obtain a full picture of program effects; and (6) multiple informants should be used to provide data about program effectiveness. In addition, the authors will argue that the field should carefully consider the amount of change that should be expected from the service models delivered.
Resumo:
Structural characteristics of social networks have been recognized as important factors of effective natural resource governance. However, network analyses of natural resource governance most often remain static, even though governance is an inherently dynamic process. In this article, we investigate the evolution of a social network of organizational actors involved in the governance of natural resources in a regional nature park project in Switzerland. We ask how the maturation of a governance network affects bonding social capital and centralization in the network. Applying separable temporal exponential random graph modeling (STERGM), we test two hypotheses based on the risk hypothesis by Berardo and Scholz (2010) in a longitudinal setting. Results show that network dynamics clearly follow the expected trend toward generating bonding social capital but do not imply a shift toward less hierarchical and more decentralized structures over time. We investigate how these structural processes may contribute to network effectiveness over time.
Case study on mobile applications UX: effect of the usage of a crosss-platform development framework
Resumo:
Cross-platform development frameworks for mobile applications promise important advantages in cost cuttings and easy maintenance, posing as a very good option for organizations interested in the design of mobile applications for several platforms. Given that platform conventions are especially important for the User eXperience (UX) of mobile applications, the usage of framework where the same code defines the behavior of the app in different platforms could have negative impact in the UX. The objetive of this study is comparing the cross-platform and the native approach for being able to determine if the selected development approach has any impact on the users in terms of UX. To be able to set a base line under this subject, study on cross-platform frameworks was performed to select the most appropriate one from a UX point of view. In order to achieve the objectives of this work, two development teams have developed two versions of the same application; one using framework that generates Android and iOS versions automatically, and another team developing native versions of the same application. The alternative versions for each platform have been evaluated with 37 users with a combination of a laboratory usability test and a longitudinal study. The results show that differences are minimal in the Android version, but in iOS, even if a reasonable good UX can be obtained with the usage of this framework by an UX-conscious design team, a higher level of UX can be obtained directly developing in native code.
Resumo:
Cross-platform development frameworks for mobile applications promise important advantages in cost cuttings and easy maintenance, posing as a very good option for organizations interested in the design of mobile applications for several platforms. Given that platform conventions are especially important for the User eXperience (UX) of mobile applications, the usage of a framework where the same code defines the behavior of the app in different platforms could have a negative impact in the UX. This paper describes a study where two independent teams have designed two different versions of a mobile application, one using a framework that generates Android and iOS versions automatically, and another team using native tools. The alternative versions for each platform have been evaluated with 37 users with a combination of a laboratory usability test and a longitudinal study. The results show that differences are minimal in the Android platform, but in iOS, even if a reasonably good UX can be obtained with the usage of this framework by an UX-conscious design team, a higher level of UX can be obtained directly developing with a native tool.
Resumo:
Tese de doutoramento, Psicologia (Psicologia Clínica), Universidade de Lisboa, Faculdade de Psicologia, 2016
Resumo:
This work was developed in the form of a case study to measure the efficiency of gait and conclude if the tested suspension systems differ in the efficiency in a various tested transtibial prostheses,based on the data provided by radiologic images, indirect calorimetry and perception of the patient. Introduction - The suspension system and the stump adjustment to the socket plays an important role in the functionality of the prosthesis, the mobility of the amputee and overall satisfaction with the device. The comfort and functional effectiveness of the prosthesis are closely related. The harmony between the residual limb and prosthesis is crucial to that this meets its function and enable effective March and allow the amputated the continuity of their Daily day activities, keeping the stump functional. Comfort and functional effectiveness of the prosthesis are closely related, suspension systems should prevent excessive longitudinal and rotational transverse displacement of the stump within the socket, these systems should help stabilize and enhance the connection of the prosthesis to the residual limb, reducing the pistonning, increased proprioception and providing a more natural gait.