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971.
An assessment of social sciences coverage by four prominent full-text online aggregated journal packages 总被引:1,自引:0,他引:1
The cost effectiveness and quality of full-text journals are analyzed for four prominent online aggregated journal packages: EBSCOhost Academic Search FullTEXT, UMI Proquest Direct Periodicals Research II, IAC’s Expanded Academic ASAP, and H.W. Wilson’s OmniFile. Price data from EBSCO’s Librarians’ Handbook are used to assess the total and average value of social sciences journals in each package. Quality of social sciences journals coverage is compared based on citation impact factors as recorded in Journal Citation Reports—Social Sciences Edition. 相似文献
972.
Dowe David L.; Gardner Steve; Oppy Graham 《The British journal for the philosophy of science》2007,58(4):709-754
The advent of formal definitions of the simplicity of a theoryhas important implications for model selection. But what isthe best way to define simplicity? Forster and Sober ([1994])advocate the use of Akaike's Information Criterion (AIC), anon-Bayesian formalisation of the notion of simplicity. Thisforms an important part of their wider attack on Bayesianismin the philosophy of science. We defend a Bayesian alternative:the simplicity of a theory is to be characterised in terms ofWallace's Minimum Message Length (MML). We show that AIC isinadequate for many statistical problems where MML performswell. Whereas MML is always defined, AIC can be undefined. WhereasMML is not known ever to be statistically inconsistent, AICcan be. Even when defined and consistent, AIC performs worsethan MML on small sample sizes. MML is statistically invariantunder 1-to-1 re-parametrisation, thus avoiding a common criticismof Bayesian approaches. We also show that MML provides answersto many of Forster's objections to Bayesianism. Hence an importantpart of the attack on Bayesianism fails.
- Introduction
- TheCurve Fitting Problem
- 2.1 Curves and families of curves
- 2.2 Noise
- 2.3 Themethod of Maximum Likelihood
- 2.4 ML and over-fitting
- 2.2 Noise
- 2.1 Curves and families of curves
- Akaike's Information Criterion(AIC)
- The Predictive Accuracy Framework
- The Minimum MessageLength (MML) Principle
- 5.1 The Strict MML estimator
- 5.2 Anexample: Thebinomial distribution
- 5.3 Properties ofthe SMML estimator
- 5.3.1 Bayesianism
- 5.3.2 Languageinvariance
- 5.3.3Generality
- 5.3.4 Consistencyand efficiency
- 5.3.2 Languageinvariance
- 5.4 Similarity to false oracles
- 5.5 Approximationsto SMML
- 5.2 Anexample: Thebinomial distribution
- 5.1 The Strict MML estimator
- Criticisms of AIC
- 6.1 Problems with ML
- 6.1.1 Smallsample biasin a Gaussian distribution
- 6.1.2 Thevon Misescircular and von Mises—Fisherspherical distributions
- 6.1.3 The Neyman–Scottproblem
- 6.1.4 Neyman–Scott,predictive accuracyandminimum expected KL distance
- 6.1.2 Thevon Misescircular and von Mises—Fisherspherical distributions
- 6.2 Otherproblems with AIC
- 6.2.1 Univariate polynomial regression
- 6.2.2 Autoregressiveeconometric time series
- 6.2.3 Multivariatesecond-orderpolynomial modelselection
- 6.2.4 Gapor no gap:a clustering-like problem forAIC
- 6.2.2 Autoregressiveeconometric time series
- 6.3 Conclusionsfrom the comparison of MML and AIC
- 6.1.1 Smallsample biasin a Gaussian distribution
- 6.1 Problems with ML
- Meeting Forster's objectionsto Bayesianism
- 7.1 The sub-family problem
- 7.2 Theproblem of approximation,or, which framework forstatistics?
- 7.1 The sub-family problem
- Conclusion
- Details of the derivation of the Strict MMLestimator
- MML, AIC and the Gap vs. No Gap Problem
- B.1 Expectedsize of the largest gap
- B.2 Performanceof AIC on thegap vs. no gap problem
- B.3 Performanceof MML in thegap vs. no gap problem
- B.2 Performanceof AIC on thegap vs. no gap problem
- B.1 Expectedsize of the largest gap
973.
The effectiveness of online instructional videos in the acquisition and demonstration of cognitive,affective and psychomotor rehabilitation skills 下载免费PDF全文
Darren Cooper Steve Higgins 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(4):768-779
The use of instructional videos to teach clinical skills is an ever growing area of e‐learning based upon observational learning that is cited as one of the most basic yet powerful learning strategies. The aim of the current study is to evaluate the effectiveness of online instructional videos for the acquisition and demonstration of cognitive, affective and psychomotor skills among undergraduate students, throughout formative assessments with two different durations of instructional videos. The research suggests that the use of videos to support traditional learning should be encouraged. While a conclusive evidence—base for their usage has not yet been established they are a medium which is likely to benefit a proportion of a cohort, and it is very unlikely that they will be harmful to students' learning. 相似文献
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976.
In America the ethic of individual achievement has always been balanced by complementary norms of group action. Blacks, however, have been handicapped by a lack of the in-group loyalty required for a united struggle against racial oppression. Black power ideology was conceived as a sociotherapy to increase the level of black group cohesion. This study was designed to provide much needed data on the success of the “therapy.” A survey of 611 black high school students and 93 black college students yielded little evidence that verbally professed endorsement of black power ideology was translated into action. In an experiment. 323 black high school students manifested a consistent tendency to be less helpful to scientists identified as black than to unidentified scientists, regardless of the students' claimed level of black power orientation. 相似文献
977.
978.
Connor S 《New scientist (1971)》1983,100(1385):559
979.
980.
Michle Clarke 《Learned Publishing》1996,9(4):219-223
Considers the indexing of scientific and medical periodicals, covering the need for indexes, the effect on information retrieval of the electronic revolution, types of journals and entries, the process of indexing, cumulation, and publisherAndexer relations 相似文献