Important Statistics BY Assist. Prof. Benchamat Laksaniyanon, Phd Phd@University of North Texas, USA ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Who hate statistics!! Significant test Types of Statistics Significant test & p-value Null hypothesis vs alternative/research hypothesis Type I & II errors Types of Statistics Descriptive statistics Inferential statistics ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Significant test & p-value Significant level is defined as the degree of risk that the researcher set for testing or rejecting a null hypothesis when the null hypothesis is true (Salkind, 2011). .05 and .01 are also known as the rejection level or significant level (Howell, 2010). [If .05] expect that no more than 5 times out of 100 times will decide to keep the alternative (research) hypothesis and it is wrong. ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Hypotheses Null hypothesis (H0) Research (alternative) hypothesis (H1) No difference [=] Research (alternative) hypothesis (H1) Difference [≠,<, >] Unknown --- two tails Known ---one tails Making Decision on H0 [hypothesis testing] The result of p-value ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Type I & II errors Null hypothesis (H0) No difference [=] Research (alternative) hypothesis (H1) Difference [<, >] Unknown --- two tails Known ---one tails ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Type I & II errors ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Descriptive and Inferential Statistics Population A parameter e.g. 𝜇=14 inferential statistics Sample A statistic e.g. 𝑥 =14 Descriptive statistics ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Descriptive and Inferential Statistics descriptive statistics are used to describe the characteristics of the data set (its measure is called a statistic) while the inferential statistics are used to make inferences from the data set to the population (its measure is called a parameter) (Salkind, 2011). Similarly, Hinkle, Wiersma, and Jurs (2003) stated that both of them are as a collection of methods, but while descriptive statistics is used for classifying and summarizing numerical data, inferential statistics is used for making inferences the characteristics of the population from the corresponding characteristics of the sample. ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Do I have anything? Where does it come from? What should I report? Do I have anything? Where does it come from? ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Good Report: Statistical significance & effect size Do you have anything? Null Hypothesis Significance Testing (NHST). Reject the null hypothesis? The p-value is used as a criterion. The result from p-values obtained, however, is not enough for scholarly paper (Sun, Pan, & Wang, 2010). Where does it come from? Effect size must be reported also (Sun, Pan, & Wang, 2010; Henson, 2002). ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Results Improve to make it strong? In Data Analysis Part Topics Data screening Missing data? Outliers? Required assumptions met? Main statistics used (Specifically) Right steps? Reliability & Validity? ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

Analysis & Statistics Acknowledgment of [specific] statistics (Examples) T-test Sample-population Independent variables Same variable ANOVA MANOVA ANCOVA Regression CCA DDA FA SEM HLM F = t2 ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016

See you again tomorrow for (fundamental) “Statistics”! ผศ.ดร.เบญจมาส ลักษณิยานนท์ 2016