Applying LDA Topic Modeling in Communication Research: Toward a Valid and Reliable Methodology     

Daniel Maier  A. Waldherr  P. Miltner  G. Wiedemann  A. Niekler  A. Keinert 《Communication methods and measures》2018,12(2-3):93-118

ABSTRACT

Latent Dirichlet allocation (LDA) topic models are increasingly being used in communication research. Yet, questions regarding reliability and validity of the approach have received little attention thus far. In applying LDA to textual data, researchers need to tackle at least four major challenges that affect these criteria: (a) appropriate pre-processing of the text collection; (b) adequate selection of model parameters, including the number of topics to be generated; (c) evaluation of the model’s reliability; and (d) the process of validly interpreting the resulting topics. We review the research literature dealing with these questions and propose a methodology that approaches these challenges. Our overall goal is to make LDA topic modeling more accessible to communication researchers and to ensure compliance with disciplinary standards. Consequently, we develop a brief hands-on user guide for applying LDA topic modeling. We demonstrate the value of our approach with empirical data from an ongoing research project.  相似文献   

Performance differences when using 26- and 29-inch-wheel bikes in Swiss National Team cross-country mountain bikers     

Thomas Steiner  Beat Müller  Thomas Maier  Jon Peter Wehrlin 《Journal of sports sciences》2016,34(15):1438-1444

The purpose of this study was to analyse the effect of bike type – the 26-inch-wheel bike (26“ bike) and the 29-inch-wheel bike (29“ bike) – on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26“ bike and three trials on a 29“ bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29“ bike (section A) or the 26“ bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes’ experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29“ bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29“ bike as better for performance in general, passing obstacles and traction. The 29“ bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26“ bike.  相似文献   

Active recovery of the finger flexors enhances intermittent handgrip performance in rock climbers     

Jiří Baláš  David Giles  Jan Kodejška  Michaela Panáčková  Simon Fryer 《European Journal of Sport Science》2016,16(7):764-772

This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time–force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time–force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P?P?P?相似文献   

Images of the family: on interviewing young children about their social concepts     

Michaela Ulich  Pamela Oberhuemer 《International Journal of Early Years Education》1993,1(1):13-22

The empirical study explores children's perceptions of the family and family membership. 300 four‐, six‐ and eight‐year‐old children were interviewed with a semi‐structured ‘Family Concept Interview’. Interview strategies and research findings are presented and discussed. Establishing field entry rituals and determining appropriate modes and levels of discourse are important factors for creating an interview situation in which children are continuously attentive and motivated. Findings indicate that children do have a generalised and complex image of the family. The majority construct relatively large families with two or more children; over half the children include grandparents (father and mother)’, but one‐parent‐households are also accepted as ‘a family’, regardless of the child's own family situation. ‘Common residence’ is an important but not a necessary criterion for family membership. The findings show significant age differences concerning some aspects of children's family concepts.  相似文献   

Summation and configuration between and within sensory modalities in classical conditioning of the rabbit     

E. James Kehoe  Amanda J. Horne  Peter S. Horne  Michaela Macrae 《Learning & behavior》1994,22(1):19-26

Three experiments examined “atomistic” and “configurai” processes in stimulus compounding using the rabbit’s conditioned nictitating membrane response. Two conditioned stimuli (CSs) were trained separately and then tested together in a compound. Animals trained with CSs from different modalities—namely, tone and light—showed summation in both acquisition and extinction. That is, the probability of a response to the compound could be predicted by the statistical sum of responding to the CSs. In contrast, animals trained with CSs from the auditory modality, tone and noise, showed a level of responding to the tone + noise compound that was the same as that of the CSs, well under the level predicted by the statistical sum of responding to the CSs. In conclusion, atomistic processes appear to predominate in cross-modal compounding. Configurai processes may occur during compounding within the auditory modality, but atomistic alternatives—namely, common elements and selective attention hypotheses—may be able to explain the results.  相似文献   

One size fits all?: Towards a differentiated regional innovation policy approach     

Franz Tödtling  Michaela Trippl 《Research Policy》2005,34(8):1203-1219

Innovation has moved to the foreground in regional policy in the last decade. Concrete policies were shaped by “best practice models” derived from high-tech areas and well performing regions. These are often applied in a similar way across many types of regions. Here an attempt is made to show that there is no “ideal model” for innovation policy as innovation activities differ strongly between central, peripheral and old industrial areas. In this paper we analyse different types of regions with respect to their preconditions for innovation, networking and innovation barriers. Based on this classification different policy options and strategies are developed.  相似文献   

Reliability and Validity of Real-Time Response Measurement: a Comparison of Two Studies of a Televised Debate in Germany   总被引：1，自引：0，他引：1  

Maier  Jurgen; Maurer  Marcus; Reinemann  Carsten; Faas  Thorsten 《Int. Journal of Public Opinion Research》2007,19(1):53-73

This paper investigates the reliability and validity of real-timeresponse measurements (RTR). It is based on a comparison oftwo quasi-experimental studies independently conducted on thesecond televised debate of the two major candidates for chancellorin the 2002 German federal election campaign. Participants inBamberg and Mainz—two mid-sized German cities—followedthe debate on a large-scale screen. The viewers’ immediatereactions to the candidates were measured in real-time. In termsof technicalities and substance, both quasi-experiments differedin several important respects. For example, the system usedin Mainz was based on a control unit with a 7-point scale andyielded one merged metric dimension for both candidates. TheBamberg system measured positive and negative impressions ofthe candidates independently, yielding categorical data. Despitethese operational differences, the results show that both methodsrender reliable results that also meet the criteria of face,construct, and criterion validity. Hence, RTR measurements providevaluable, unique insights into subjective immediate reactionsto candidates in televised debates and help to explain post-debateperceptions and attitudes. Received for publication March 23, 2005. Revision received December 14, 2005.  相似文献   

Experiencing spiritual aspects outdoors in the winter: a case study from the Czech Republic using the method of systemic constellations     

Ivo Jirásek  Miroslava Jirásková  Petra Majewská  Michaela Bolcková 《British Journal of Religious Education》2017,39(2):122-148

The article focuses on spirituality on two semantic levels: the first one analyses participants’ experiences during a winter expeditionary course on snowshoes and considers the question of whether residing in the winter landscape with a community of other people may acquire a spiritual dimension in spite of the non-religious environment. The second level verifies whether the trans-rational method of systemic constellations may be used as a research tool, that is, as a specific source for data collection (different from other sources and methods). The research applied a phenomenological approach to the analysis of unstructured interviews (n = 12) and constellation insights; the result confirmed indisputably that certain kinds of experiences obtained in a completely non-religious environment (namely, during a winter expedition on snowshoes in the mountains) can be considered spiritual. The answer to the second question is also positive, since the application of systemic constellations results in different data in comparison with their verbal acquisition. Symbolic images that point out the system and its unaccepted elements deepen the understanding of both the individual and the nature of their spiritual experience.  相似文献   

Educational upward mobility – practices of social changes     

Michaela Brockmann 《International Studies in Sociology of Education》2017,26(1):98-100

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The assessment life cycle: A model for analysing institutional e‐assessment development     

Jane McNeil  Michaela Borg  Carmen Tomas 《British journal of educational technology : journal of the Council for Educational Technology》2011,42(2):E21-E24

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