1,721,328 research outputs found
Strobe-Statement: Wie berichtet man eine Beobachtungsstudie?
No full textEine internationale Gruppe schlägt eine Checkliste mit 22 Punkten vor, die von Studiendesign und Methoden bis zum Umgang mit quantitativen Variablen reicht
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Non-dissemination and dissemination Bias in qualitative research: Empirical evidence and conceptualisation
No full textBackground: Treatment effects in health-care are best studied by quantitative studies that use quantitative methods to assess the effects of an intervention and report their results as numerical data. Qualitative research in health-care is used to understand factors that affect whether interventions are acceptable and feasible and whether interventions are fully and effectively implemented and how people rate the importance of different health outcomes. In addition, qualitative findings can influence the conceptualization, development, and implementation of interventions in health-care. Findings from qualitative research can inform decisions on the use of evidence-based health-care interventions and contribute to policy decisions in these fields. Lastly, through qualitative research, theories can be developed and explanatory hypotheses can be created. Systematic reviews are a way of synthesising evidence from individual studies and summarise the available scientific evidence for a specific question by following a strict scientific methodology. In order to assess the certainty of the findings from reviews of quantitative studies of the effectiveness of interventions, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was developed. Qualitative evidence syntheses are a way of systematically summarising qualitative evidence. In qualitative evidence synthesis, evidence from individual qualitative research studies addressing similar research questions or phenomena of interest is analysed and interpreted jointly. The GRADE-CERQual (Confidence in the Evidence from Reviews of Qualitative research) approach was designed specifically to assess how much confidence to place in findings from qualitative evidence syntheses. Dissemination bias describes a systematic error occurring from non-dissemination of studies and individual findings and the key concern with that is the (non-)dissemination of studies due to the nature of their content and message. Dissemination bias is one concern that potentially weakens the assumption of “high confidence”. Time-lag bias, language bias, grey literature bias, and truncation bias are underlying mechanisms that fuel dissemination bias. Empirical evidence has shown that a considerable proportion of quantitative research in clinical effectiveness research remains unpublished once completed. Because statistically significant and positive results have a higher probability of publication, it has been found that dissemination bias led to an overestimation of the reported effects of health interventions. Aim: First, to explore the extent of non-dissemination in qualitative research and stakeholders’ reasons for non-dissemination of qualitative research studies and individual findings. Second, to explore stakeholders’ views and experiences about the relevance of dissemination bias in qualitative research and how dissemination bias might be detected and interventions that might decrease dissemination bias in qualitative research. This includes reflection on the definition and delineation of dissemination bias in qualitative research and consideration of how dissemination bias might occur and how it can be detected. Methods: To address these aims, research with four main components was conducted. These include 1) a cross-sectional survey, 2) a follow-up cohort study of qualitative conference abstracts, 3) group discussions and 4) expert consultations. A cross-sectional survey approach was used to gather data regarding non-dissemination and dissemination bias in qualitative research from qualitative researchers, authors of qualitative evidence syntheses, peer reviewers and editors of scientific journals. Overall, the survey comprised 30 closed and open-ended questions. In order to identify suitable participants with experience in qualitative research, authors of published qualitative studies were searched for. A validated search strategy for qualitative studies was used in Ovid MEDLINE. Participants were also invited through various relevant mailing lists which contained researchers who were involved in qualitative research. The final survey was delivered online using Survey Monkey. All available responses were included in the final analyses and it was planned to report the overall response rate. A descriptive statistical analysis of frequencies and proportions was automatically generated by the survey software and used for the analysis of the survey responses. To explore relations between selected participants’ answer options, a bivariate Pearson correlation analysis was conducted in R Studio for the normally distributed data. Qualitative survey data were analysed using an inductive thematic analysis in MAXQDA. Empirical evidence for this thesis stems from a follow-up study of qualitative abstracts. The study sample was drawn from the conference proceedings of the United Kingdom Royal College of Nursing Research Conferences in 2015 and 2016. All abstracts accepted for oral presentations and posters were potentially eligible. To be included in this cohort study, all abstracts were scrutinised for the following criteria: i) description of a qualitative study, ii) description of a mixed-methods study or a programme description with at least one qualitative element iii) evidence syntheses of qualitative research findings. Subsequent full publications of the studies presented in abstracts were searched for in MEDLINE via OVID, in the Cumulative Index to Nursing & Allied Health Literature (CINAHL) and Google Scholar. Data from the cohort study were summarised with univariate descriptive statistics. Proportions and 95% confidence intervals (CIs) were calculated. Fisher’s exact test was calculated to examine associations between study characteristics and proportions of abstracts with a full publication. Logistic regression was used to evaluate an association between numerical study characteristics and a subsequent full publication. Time to publication was visualised with a Kaplan-Meier curve. Factors potentially associated with time to publication were evaluated with Cox regression analysis. All analyses were conducted in R Studio. Group discussions were selected to understand experts’ behaviours, views, and experiences concerning non-dissemination of qualitative research and dissemination bias in qualitative research. Researchers with knowledge in the field of qualitative research and/ or dissemination bias were consulted through two group discussions held at international scientific conferences which were attended by health researchers, experts in health research methods, and systematic review authors. Additionally, a pragmatic research approach was taken to develop and advance concepts concerning dissemination bias in qualitative research. This entailed iterative consultations with experts in dissemination bias and qualitative evidence synthesis, and developing consensus through multiple face-to-face meetings and teleconferences with these international experts. Protocols from group discussions and expert consultations were transcribed and coded by one researcher. An inductive thematic analysis of all available notes was conducted following the same method as for the qualitative survey responses. Data were documented and structured in a way that allows easy access and reusability of the data by third parties. Original, complete data are stored in the existing local server environment of the Medical Center - University of Freiburg, which allows secure long-term storage of data. Results: Overall, 1032 people initiated the survey of whom 756 (73.3%) completed the survey. In the survey, more than 50% of the respondents reported that one or more of their qualitative studies had not been published in a peer-reviewed journal (≥1 study not published: 68.1%) or another publicly accessible format (≥1 study not published: 51.7%). One-third reported that important individual findings were missing in one or more of their published reports (n=288, 35.6%). Researchers reported that the most important reasons for non-dissemination were that publication was still planned, (n=147, 35.7%), resource constraints, (n=146, 35.4%), and rejection from journals (n=134, 32.5%). Peer reviewers and editors reported that the methodological quality and reporting quality of qualitative studies were the primary reasons for rejecting manuscripts. Most respondents reported that they agreed that non-dissemination of qualitative research has negative impacts on health research (n=614, 76.6%), health policy (n=581, 72.6%) and health-care (n=572, 71.2%). Researchers reported having mixed views about whether publicly accessible repositories for registration of qualitative studies and dissemination of qualitative study findings might decrease dissemination bias. For the cohort study a total of 111 abstracts (96 oral presentations and 15 poster presentations) presented in the year 2015 were included. From the conference in 2016, 159 abstracts (114 oral presentations and 45 poster presentations) were included. The cohort study found that almost one-third, that are 91 of 270 (33.70%; 95% CI 28.09 to 39.68%), of qualitative studies presented at an international nursing research conference did not result in full publication five years after presentation. Studies presented as oral presentations were associated with subsequent full publication when compared to poster presentations. Studies presented by first authors with university affiliations were also associated with subsequent full publication when compared to studies presented by authors without university affiliation. Median time to full publication was 11 months (95% CI 9 to 14 months). Only presentation format impacted on the time to publication, with studies presented as oral presentations being associated with a quicker conversion to full publication compared to studies presented as posters.The two group discussions were attended by about 10 and 30 participants, respectively. Expert consultations involved nine experts with experience in qualitative research or dissemination bias in health research. In group discussions and expert consultations dissemination bias in qualitative research was perceived to be a relevant issue for the research community and further research on this topic seemed valuable to advance the knowledge in the field. The definition of dissemination bias was accepted as a reasonable, comprehensive, and comprehensible description of the issue. Detection of dissemination bias in qualitative research seemed most promising if multiple sources of data are available for triangulation of data. It was agreed that the issue of dissemination bias in qualitative research might likely be present and relevant for qualitative research, and that this bias and underlying mechanisms should be explored systematically in more depth. Discussion: The resource and time-efficient approach of the survey, cohort study and group discussion with convenience sampling provided first findings quickly. This seemed most adequate to conduct exploratory work in this area of research, namely, taking stock of rates of non-dissemination in qualitative research as well as the views towards and experiences regarding dissemination bias in qualitative research and its importance. Moreover, the survey is one of the largest studies investigating the issue of non-dissemination in qualitative research in health science. The survey was conducted online and a considerable strength of this study’s sample is its large sample size and broad variety of respondents in terms of current country of work, main publication language, and age. The strength of the cohort study are i) a relatively long duration of follow-up, ii) a comprehensive search for full publications and iii) thorough matching of abstracts and full publications. The cohort study’s findings are limited by the fact that only one conference was sampled and the sample size was limited accordingly. Data extraction as well as matching of abstracts and full publications were conducted mainly by one researcher with a second researcher checking the extracted data and the matching. Generally, the research findings might be subject to design specific error that can impact on their reliability and decrease their external validity. Specification error, non-response error, measurement error, and processing error are plausible non-sampling errors that might have impacted on the survey’s finding and the findings of the group discussions and the expert consultations. In the cohort study, the selection of additional factors for the statistical analysis might have yielded relevant and meaningful results. The findings of this research are not necessarily generalisable to a general population of researchers, peer reviewers and editors and should be interpreted cautiously.Conclusions: The research presented here found that self-reported rates of non-dissemination in qualitative research are substantial. The cohort study found that for at least one-third of qualitative studies presented as a conference abstracts a subsequent full publication could not be retrieved. Oral presentations and studies from first authors with a university affiliation were found to be associated with a subsequent full publication in the examined cohort. From the survey, group discussions and expert consultations it became clear that dissemination bias is perceived as a relevant issue among qualitative researchers that warrants future research. Underlying mechanisms that impact on dissemination bias in quantitative research seemed likely to be relevant for qualitative research to experts. All findings should be interpreted with caution and under consideration of the limitations of all individual studies presented here. This research contributed towards conceptualising and defining dissemination bias in qualitative research and underlying mechanisms, and generated empirical evidence on non-dissemination in qualitative research. The findings of this research will inform the development and refinement of the respective component in the GRADE-CERQual framework to allow sound assessments of the confidence in qualitative evidence syntheses.The research findings of the project were published in international, peer-reviewed, open-access journals as original publications (1-4). In addition, the study results were presented at national and international conferences and congresses and were discussed with the academic community
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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