LangTest: An easy-to-use stats calculator Punjaporn P. punjaporn.poj@kmutt.ac.th 7-11-2016

Class B performed better Summarise data (20 to 1) Student Class A Class B 1 4 8 2 3 5 6 7 9 10 11 12 13 14 15 16 17 18 19 20 4, 5 Class B performed better Summarise data (20 to 1) Identify relationships Basic calculation Class A’s average score Class B’s average score Compare 2 average scores Reduce numbers More simple, understandable, and meaningful

Purpose: To compare 2 average scores Student Class 1 Class 2 1 8 9 2 6 3 4 5 7 10 11 12 13 14 15 16 17 18 19 20 Purpose: To compare 2 average scores Question: Is there a difference between 2 average scores?

Difference >2 2 Y N Y N #datasets Normal distribution & equal variances? Paired data? Paired t-test Independent samples t-test Mann Whitney U test >2 2 Y N Y N http://esa21.kennesaw.edu/modules/basics/exercise3/3-8.htm

Independent samples t-test Compare 2 means (2 independent groups) Assumptions: Normal distribution (test of normality) Equal variances (test for equality of variances) Values: t-value, p-value Related value: effect size

WWW Functions Write yours Commercial packages Programming language Web-based stats tools Photo: https://worldhailnetwork.com/hail-repair-tools/

Excel Assumptions: a normal distribution, equal variances Values: t-value, p-value Related value: effect size 0.05

SPSS ???

SPSS

SPSS Assumptions: a normal distribution, equal variances Values: t-value, p-value Related value: effect size

WWW

WWW Assumptions: a normal distribution, equal variances Values: t-value, p-value Related value: effect size

R ???

Not require extra preparation Advantages Drawbacks Excel – functions – type yours Easy Variety of tools Not require to learn new method Flexible Poor Human error SPSS Commonly-used, similar feel to excel Easy to find resource Well-structured report Output is kept separate from the data Large learning load Require to prepare data Online Limited to certain stats Provide only numerical values R (Programming language) Free Full-functions High-quality of figures and plots Large online community Growing community of users, contributing to useful packages Large learning load - programming Difficult to learn Very complex data structures Require a good understanding of different data types Require top skills for high performance Give values needed Accurate Not require extra preparation Provide graphical data Practical, understandable

LangTest Developed by Associate Professor of Applied Linguistics Based on R-programming language Simple to advanced statistics calculations To summarise and describe data To identify relationships Give values needed, also related values Accurate Not require extra preparation Provide graphical data Practical and understandable NOT require special skills Cut & Paste!

LangTest Exploratory Factor Analysis Basic Statistics Calculator Cronbach's Coefficient Alpha Basic Statistics Calculator Learning by Doing Stats (t-test Tutorial) Comparing Two Independent Samples Comparing Paired Samples Effect Size Calculator 1 (Means, SDs, Ns) ANOVA Non-parametric Tests Correlation Regression Analysis Chi-square Test McNemar's Test and Cochran's Q Test Cohen's Kappa and Other Interrater Agreement Measures Cluster Analysis Exploratory Factor Analysis Principal Component Analysis Correspondence Analysis Tree-based Models Structural Equation Modeling (SEM) Binary (1-0) Data Converter Screening Data Classical Test Theory (Item Analysis) Criterion-referenced Testing (Item Analysis) Generalizability Theory Rasch Model (1PL IRT) Item Response Theory Meta-analysis Text Analysis

Basic calculations #data set Purpose Statistics Summarise data Mean 1 Summarise data by giving a central estimate Sd Summarise extent of distribution of data Identify relationships t-test 2 Compare 2 means t-value, p-value Correlations Strength of relationships r-value, p-value

Langtest: http://langtest.jp/ mean, Sd Basic Statistics Calculator

Langtest: http://langtest.jp/ t-test Comparing Two Independent Samples Comparing Paired Samples Assumptions: normal distribution, equal variances Values: t-value, p-value Related value: effect size

Langtest: http://langtest.jp/ Correlations Correlation Pearson’s correlation Spearman’s rank

N, mean, sd, med, min, max, range, skewness, kurtosis Histogram Basic statistics Distribution and test of normality Stats, p-value Specific graphical data Graphical method Numerical N, mean, sd, med, min, max, range, skewness, kurtosis Histogram Box-plot Q-Q plot K-S test Wilk’s test - Correlation yes r, p Scatter plot

yes Histogram Box-plot K-S test Wilk’s test Lavene’s test t, p Mean Basic statistics Distribution and test of normality Test for equality of variances Stats, p-value Specific graphical data Effect size Related values Graphical method Numerical Ind. t-test yes Histogram Box-plot K-S test Wilk’s test Lavene’s test t, p Mean Diff. ES: d, g Corr. ES: r, z, OR, Log OR Mann-Whitney U-test (normality not assumed) Welch (equal Paired Changes of individual Wilcoxon signed-rank test (normality