In this paper, we assume the error distribution of one-way ANOVA as alpha-skew normal distribution. Alpha-skew gives us exibility for modelling data which has heavy tailness, skewness, bimodality and also symmetricity. We obtain maximum likelihood estimator model parameters test statistics based on these estimators. Monte Carlo simulation study states that estimators interest are more efficient...

In this example, we reanalyze the soybean yield data, but treat the explanatory variable as a categorical (ordinal) variable with 4 levels and use one−way anova to test for a significant SO2 effect. We can think of the data as samples from four different populations, corresponding to the SO2 concentration the chambers received, with possibly different means. In each treatment group we have 3 ob...

I. Definition and Applications...............................................................................2 II. Two-Way ANOVA prerequisites.......................................................................2 III. How to use the Two-Way ANOVA tool?...........................................................3 A. Parametric test, assume variances equal. .........................................

Last week we learned about one-way designs. They examine several levels of a single factor. For instance, we might examine the effect of StudyType (independent variable) on LanguagePerformance (dependent variable). Classroom study Self-study Control Perhaps we think that the StudyType manipulation might only affect one gender or the other. We could do a two-way design whether a second factor, G...

Download the file ANOVA1.sas from my SAS programs page and run it. The contrived data (I created them with SAS' normal random number generator) are within the program. We shall imagine that we are evaluating the effectiveness of a new drug (Athenopram HBr) for the treatment of persons with depressive and anxiety disorders. Our independent variable is the daily dose of the drug given to such per...

ANOVA is one of the most important tools in comparing treatment means among different groups repeated measurements. The classical F test routinely used to if are same across groups. However, it inefficient when number or dimension gets large. We propose a smoothing truncation deal with this problem. It shown theoreticall...