--- title: "Analysis of Variance" author: "Renae L. Shrum" output: beamer_presentation: colortheme: beaver fonttheme: professionalfonts theme: Szeged --- ## Anova Terms III $t=\text{\# treatment groups}$ $n_i=i^{th} \text{group sample size}$ $N=\sum n_i=\text{total observations}$ $s_i^2=i^{th} \text{treatment group variance}$ $\bar y_{i\cdot}=i^{th} \text{treatment group mean}$ $\bar y_{\cdot\cdot}=\text{grand mean}$ $df_{Tr}=$ treatment degrees of freedom $df_E=$ Error degrees of freedom $df_{Total}=$ Total degrees of freedom $SSTr=$ Sum of squares treatment $SSE=$ Sum of squares error $TSS=$ Total sum of squares $MSTr=$ Mean square treatment $MSE=$ Mean square error ## Anova Formulas $df_{Tr}=df_1=t-1$ $df_E=df_2=N-t$ $df_{Total}=df_1+df_2=N-1$ $\bar y_{\cdot\cdot}=\frac{\sum y_{ij}}{N}=\frac{\sum \bar y_{i\cdot}}{t}$ $SSTR=\sum n_i(\bar y_{i\cdot}-\bar y_{\cdot\cdot})^2$ $=n_1(\bar y_1-\bar y_{\cdot\cdot})^2+n_2(\bar y_2-\bar y_{\cdot\cdot})^2+\cdots+n_t(\bar y_t-\bar y_{\cdot\cdot})^2$ $SSE=\sum(y_{ij}-\bar y_{i\cdot})^2=\sum s_i^2(n_i-1)$ $=s_1^2(n_1-1)+s_2^2(n_2-1)+\cdots+s_t^2(n_t-1)$ $TSS=SSTR+SSE$ $MSTr=\frac{SSTr}{df_{Tr}}=\frac{SSTR}{t-1}$ $MSE=\frac{SSE}{df_E}=\frac{SSE}{N-t}$ $F=\frac{MSTr}{MSE}$ ## Anova table | Source of Variation | df | SS | MS | F | pvalue | | :-------------------|:-----|:-----|:-----|:-----------------|:------------------| | Treatment | $t-1$| SSTr | MSTr |$\frac{MSTr}{MSE}$|$P(F\geq F_{calc})$| | Error | $N-t$| SSE | MSE | | | | Total | $N-1$| TSS | | | |