Yıl: 2020 Cilt: 7 Sayı: 2 Sayfa Aralığı: 255 - 265 Metin Dili: İngilizce DOI: 10.21449/ijate.656077 İndeks Tarihi: 20-11-2020

Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison

Öz:
Checking the normality assumption is necessary to decide whether aparametric or non-parametric test needs to be used. Different ways are suggestedin literature to use for checking normality. Skewness and kurtosis values are one ofthem. However, there is no consensus which values indicated a normal distribution.Therefore, the effects of different criteria in terms of skewness values weresimulated in this study. Specifically, the results of t-test and U-test are comparedunder different skewness values. The results showed that t-test and U-test givedifferent results when the data showed skewness. Based on the results, usingskewness values alone to decide about normality of a dataset may not be enough.Therefore, the use of non-parametric tests might be inevitable.
Anahtar Kelime:

Belge Türü: Makale Makale Türü: Araştırma Makalesi Erişim Türü: Erişime Açık
  • Abbott, M.L. (2011). Understanding educational statistics using Microsoft Excel and SPSS. United States: Wiley & Sons, Inc.
  • Altman, D.G. (1991). Practical statistics for medical research. London: Chapman and Hall
  • Bendayan, R., Arnau, J., Blanca, M.J. & Bono, R. (2014). Comparison of the procedures of Fleishman and Ramberg et al. for generating non-normal data in simulation studies. Anales de Psicología, 30(1), 364-371. https://dx.doi.org/10.6018/analesps.30.1.135911
  • Bulmer, M. G. (1979). Principles of statistics. Mineola, New York: Dover Publications Inc.
  • Büyüköztürk, Ş., Çokluk, Ö. & Köklü, N. (2014). Sosyal bilimler için istatistik (15th Edition). Ankara: Pegem Akademik.
  • Blanca, M.J., Arnau, J., Lopez-Montiel, D., Bono, R. & Bendayan, R. (2013). Skewness and kurtosis in real data samples. Methodology, 9(2), 78–84. https://dx.doi.org/10.1027/1614- 2241/a000057
  • Blanca, M.J., Alarcon, R., Arnua, J., Bono, R. & Bendayan, R. (2017) Non-normal data: Is ANOVA still a valid option? Psicothema, 29(4), 552-557. https://dx.doi.org/10.7334/psi cothema2016.383
  • Boslaugh, S. & Watters, P.A. (2008). Statistics in a nutshell. Sebastopol, CA: O’REILLY.
  • Cain, M.K., Zhang, Z. & Yuan, K. (2017) Univariate and multivariate skewness and kurtosis for measuring nonnormality: Prevalence, influence and estimation. Behav Res, 49, 1716– 1735. https://dx.doi.org/0.3758/s13428-016-0814-1
  • Demir, E., Saatcioğlu, Ö. & İmrol, F. (2016). Uluslararası dergilerde yayımlanan eğitim araştırmalarının normallik varsayımları açısından incelenmesi, Current Research in Education, 2(3), 130-148. Retrieved from https://dergipark.org.tr/tr/pub/crd/issue/28292 /300531
  • Demirdağ, S., & Kalafat, S. (2015). Meaning in life questionnaire (MLQ): The study of adaptation to Turkish, validity, and reliability. İnönü Üniversitesi Eğitim Fakültesi Dergisi, 16(2), 83-95. https://dx.doi.org/10.17679/iuefd.16250801
  • Field, A. (2009). Discovering Statistics Using SPSS (3rd Edition). London: SAGE Publications Ltd
  • Fleishman, A.I. (1978). A method for simulating non-normal distributions. Psychometrika, 43, 521-532. https://dx.doi.org/10.1007/BF02293811
  • Ghasemi, A. & Zahediasl, S. (2012). Normality tests for statistical analysis: A guide for nonstatisticians. Int J Endocrinology & Metabolism, 10(2), 486-489. https://dx.doi.org/10.5 812/ijem.3505
  • Glass, G., Peckham, P. & Sanders, J. (1972). Consequences of failure to meet assumptions underlying the fixed effects analyses of variance and covariance. Review of Educational Measurement, 42, 237-288.
  • Huck, S.W. (2012). Reading statistics and research (6th Edition). Boston, MA: Pearson
  • Iyer, D.N., Sharp, B.M. & Brush, T.H. (2017). Knowledge creation and innovation performance: An exploration of competing perspectives on organizational systems. Universal Journal of Management, 5(6), 261-270. https://dx.doi.org/10.13189/ujm.2017 .050601
  • Kim, H. (2013). Statistical notes for clinical researchers: assessing normal distribution (2) using skewness and kurtosis. Open lecture on statistics (NA), 52-54. https://dx.doi.org/10.539 5/rde.2013.38.1.52
  • Lei, M. & Lomax, R.G. (2005). The effect of varying degrees of nonnormality in structural equation modeling. Structural Equation Modeling, 12(1), 1-27. https://dx.doi.org/10.12 07/s15328007sem1201_1
  • Miot, H.A. (2016). Assessing normality of data in clinical and experimental trials. Jornal Vascular Brasileiro 16(2) 88-91. https://dx.doi.org/10.1590/1677-5449.041117
  • Orçan, F. (2020). Sosyal bilimlerde istatistik SPSS ve Excel uygulamaları (1st Edition). Ankara: Anı Yayıncılık.
  • Park, H.M. (2008). Univariate analysis and normality test using sas, stata, and spss. Working Paper. The University Information Technology Services (UITS) Center for Statistical and Mathematical Computing, Indiana University
  • Perry, J.L., Dempster, M. & McKay, M.T. (2017) Academic self-efficacy partially mediates the relationship between scottish index of multiple deprivation and composite attainment score. Frontiers in Psychology, (8), NA. https://dx.doi.org/10.3389/fpsyg.2017.01899
  • Razali N.M. & Wah, Y.B. (2011). Power comparisons of Shapiro-Wilk, Kolmogorov-Smirnov, Lilliefors and Anderson-Darling tests, Journal of Statistical Modeling and Analytics, 2(1), 21-33. Retrieved from: https://www.researchgate.net/publication/26720 5556
  • Rachon, J., Gordan, M. & Kieser, M. (2012). To test or not to test: Preliminary assessment of normality when comparing two independent samples, BMC Medical Research Methodology, (12),81. https://dx.doi.org/10.1186/1471-2288-12-81
  • Ramos, C., Costa, P.A., Rudnicki, T., et al. (2018). The effectiveness of a group intervention to facilitate posttraumatic growth among women with breast cancer. Psycho‐Oncology, (27), 258–264. https://dx.doi.org/10.1002/pon.4501
  • Rietveld, T. & van Hout, R. (2015). The t test and beyond: Recommendations for testing the central tendencies of two independent samples in research on speech, language and hearing pathology. Journal of Communication Disorders, (58), 158-168. https://dx.doi.o rg/10.1016/j.jcomdis.2015.08.002
  • Schucany, W.R. & Tony N.G., H.K. (2006). Preliminary goodness-of-fit tests for normality do not validata the one-sample student t. Communications in Statistics – Theory and Methods, 35, 2275-2286. https://dx.doi.org/10.1080/03610920600853308
  • Şirin, Y.E., Aydın, Ö. & Bilir, F.P. (2018). Transformational-transactional leadership and organizational cynicism perception: physical education and sport teachers sample. Universal Journal of Educational Research, 6(9), 2008-2018. https://dx.doi.org/10.131 89/ujer.2018.060920
  • West, S.G., Finch, J.F. & Curran, P.J. (1995). Structural equation models with nonnormal variables: problems and remedies. In RH Hoyle (Ed.). Structural equation modeling: Concepts, issues and applications. Newbery Park, CA: SAGE.
APA Orcan F (2020). Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. , 255 - 265. 10.21449/ijate.656077
Chicago Orcan Fatih Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. (2020): 255 - 265. 10.21449/ijate.656077
MLA Orcan Fatih Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. , 2020, ss.255 - 265. 10.21449/ijate.656077
AMA Orcan F Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. . 2020; 255 - 265. 10.21449/ijate.656077
Vancouver Orcan F Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. . 2020; 255 - 265. 10.21449/ijate.656077
IEEE Orcan F "Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison." , ss.255 - 265, 2020. 10.21449/ijate.656077
ISNAD Orcan, Fatih. "Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison". (2020), 255-265. https://doi.org/10.21449/ijate.656077
APA Orcan F (2020). Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. International Journal of Assessment Tools in Education, 7(2), 255 - 265. 10.21449/ijate.656077
Chicago Orcan Fatih Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. International Journal of Assessment Tools in Education 7, no.2 (2020): 255 - 265. 10.21449/ijate.656077
MLA Orcan Fatih Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. International Journal of Assessment Tools in Education, vol.7, no.2, 2020, ss.255 - 265. 10.21449/ijate.656077
AMA Orcan F Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. International Journal of Assessment Tools in Education. 2020; 7(2): 255 - 265. 10.21449/ijate.656077
Vancouver Orcan F Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison. International Journal of Assessment Tools in Education. 2020; 7(2): 255 - 265. 10.21449/ijate.656077
IEEE Orcan F "Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison." International Journal of Assessment Tools in Education, 7, ss.255 - 265, 2020. 10.21449/ijate.656077
ISNAD Orcan, Fatih. "Parametric or Non-parametric: Skewness to Test Normality for Mean Comparison". International Journal of Assessment Tools in Education 7/2 (2020), 255-265. https://doi.org/10.21449/ijate.656077