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.
- Barnikova I.E. Ispolzovanie informatsionnykh tekhnologiy dlya otsenki razmera effekta v biomekhanicheskikh issledovaniyakh [Information technology to assess the effect in biomechanical research]. Works of Biomechanics Department of. P.F. Lesgaft University]. no. XI. St. Petersburg: R-KOPI publ., 2017. pp. 6-11.
- Samsonova A.V., Borisevich M.A., Barnikova I.E. Izmenenie mekhanicheskikh svoystv skeletnykh myshts pod vliyaniem fizicheskoy nagruzki [Changes in mechanical properties of skeletal muscles under physical activity]. Uchenye zapiski universiteta im. P.F. Lesgafta. 2017. no. 2 (144). pp. 221-224.
- Bernards J.R., Sato K., Haff G.G., Bazyler C.D. Current Research and Statistical Practices in Sport Science and a Need for Change Sports. 2017. Vol. 5(4) P. 87.
- Cohen J. Statistical Power Analysis for the Behavioral Sciences. New York: Lawrence Erlbaum Associates, 1988. 568 p.
- Cohen J. The Earth Is Round (p < .05). American Psychologist. 1994. Vol. 49(12) pp. 997-1003.
- Ferguson C.J. An Effect Size Primer: A Guide for Clinicians and Researchers. Professional Psychology: Research & Practice.2009. No.40. pp.532-538.
- Fritz C.O., Morris P.E., Richler J.J. Effect Size Estimates: Current Use, Calculations, and Interpretation. Journal of Experimental Psychology: General. 2012. vol. 141 (1). pp.2-18.
- Fröhlich M., Emrich E., Pieter A., Stark R. Outcome effects and effects sizes in sport sciences International Journal of Sports Science and Engineering. 2009. vol. 3(3). pp. 175-179.
- Goodman S.N. Aligning statistical and scientific reasoning. Science. 2016. Vol. 352(6290). pp.1180-1181.
- Kelley K., Preacher K.J. On effect size. Psychological Methods. 2012. vol.17. pp. 137-152.
- Kline R.B. Beyond significance testing: Reforming data analysis methods in behavioral research . Washington, DC: American Psychological Association, 2004. 325 p.
- Lakens D. Calculating and reporting effect sizes to facilitate cumulative science: a practical primer for t-tests and ANOVAs. Frontiers in Psychology. 2013. No. 4. P. 863.
- Tomczak M., Tomczak E. The need to report effect size estimates revisited. An overview of some recommended measures of effect size. Trends in Sport Sciences.2014. vol. 1. pp.19-25.