Effect sizing in the statistical sport data processing

Teoriya i praktika fizicheskoy kultury №7 2019

PhD, Associate Professor I.E. Barnikova1
Dr.Hab., Professor A.V. Samsonova1
Dr.Hab, Professor L.L. Tsipin1
1Lesgaft National State University of Physical Education, Sport and Health, St. Petersburg

Presently one of the key requirements for the international research publications is the effect size (ES) calculation, with the ES considered one of the key verifications of the practical benefits of the study findings. International research journals and publishers including those specialized in the physical education and sport matters tend to increasingly reject the study data verified by the p-values only. It is a fairly standard requirement nowadays that a study report shall specify the ES to confirm the practical benefits of the findings, confidence intervals and effective ranges of the applied criteria. It should be mentioned that the national research publications on the physical education and sport matters seldom if ever give the ES ratings. Objective of the study was to give examples of the study reports substantiated by the ES calculations to analyze the pros and cons of this statistical index. The study further analyzes the ES calculation method for the statistical hypotheses verification purposes with application of the Student t-criterion to the pre- versus post-experimental data arrays.
The proposed ES calculation procedure for related samples with application of the popular Student t-criterion for the statistical hypotheses verification is rather simple and practical for the data processing purposes. The study data and analysis demonstrate benefits of the ES calculation formula for substantiation of the study data and findings. It should be emphasized, however, that the physical education and sport research community needs a sector-specific dependable ES rating scale since every of the existing scales is still imperfect in fact.

Keywords: effect size, statistical sport data processing, effect sizing for related samples, Student t-criterion.

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