Advanced statistical methods Michal Jurajda

Statistics What is statistics?

Statistics What is statistics good for? Mass phenomenons/random events –Data management –Data description –Data analysis Statistics helps us to cope with variability of the world we live in.

Statistics Decision making. Statistics helps us to separate real effects from effects of random variation.

Statistics Descriptive statistics

Statistics Statistical induction –Drawing conclusions about population from the sample. –SE standard error SE=SD/√n –CI confidence interval 95% sample mean ± 1,96 SE

Statistics Hypotheses testing –Comparing two independent samples –Comparing two dependent variables –Paired/non-paired tests –Parametric/non-parametric tests

Statistics p value What the p-value tells to us? (type I error).

Frequency tables Chi-square test Fischer exact test

Normality testing Kolmogorov-Smirnov test Shapiro-Wilk

Multiple samples Multiple comparison procedures –ANOVA –Holm‘s test, Bonferoni method p/number of comparisons –Non-parametric test: Kruskal-Wallis ANOVA

Survival analysis Kaplan Meier‘s curves –comparison: log rank test

Logistic regresion Binary response variable (death/survival or healty/diseased) is related to „explanatory“ variable. Explanatory variable is continuous or categorial.

Cluster analysis