Solution file for additional exercise 10.1 ------------------------------------------ Dataset for additional exercise 10.2: ------------------------------------- - notation: y_ij = moisture content in j'th cheese in lot i, i = 1,2,3 (lot), j = 1,2 (cheese). - the effect of lots should be taken as random if the purpose is determination of the variability within the production (as it would seem to be), - model: y_ij = mu + A_i + eps_ij, where A_i's are assumed i.i.d. N(0,sigma_A^2) and eps_ij's are assumed i.i.d. N(0,sigma^2). - type of analysis: one-way ANOVA with random effects, - ANOVA table: Source DF F ---------------------------- Lots 2 MS(Lots)/MSE Error 3 Total 5 Dataset for additional exercise 10.3: ------------------------------------- - notation: y_ijk = content measured in sample k of material j in laboratory i, i = 1,...,11 (lab), j = 1,2,3 (material), k = 1,2 (sample), - the effect of labs should be taken as random because we have interest in the variability between the laboratories (to compute the reproducibility), - the effect of materials is fixed (the 3 concentrations are not chosen at random, and do not represent any population), - the interaction labs*material is random (because labs is random), - model: y_ijk = mu + A_i + beta_j + (AB)_ij + eps_ijk, where A_i's are assumed i.i.d. N(0,sigma_A^2), where AB_ij's are assumed i.i.d. N(0,sigma_AB^2), and where eps_ijk's are assumed i.i.d. N(0,sigma^2). - type of analysis: two-way ANOVA with mixed effects (both fixed and random), - ANOVA table: Source DF F ---------------------------------------- Labs 10 MS(Labs)/MS(L*M) Materials 2 MS(Mat)/MS(L*M) Labs*Materials 20 MS(L*M)/MSE Error 33 Total 65 Dataset for additional exercise 10.4: ------------------------------------- - notation: y_ijk = blood-pH value of k'th mouse in j'th litter of strain i, i = 1,2 (strain: pHH, pHL), j = 1,...,7 (litter, within strains), k = 1,2,3,4 (mouse), - hierarchical structure in data: mice within litters (within strains), - the factor litter may be considered nested within strain, because different litters are used for the two strains (there is no link between litter no. 1 in strain pHH and strain pHL), - the effect of litter(strain) must be taken as random, * by the rule that hierarchical levels must be random effects, * in order to enable a comparison between strains (otherwise only comparisons between litters is possible, if there is variation between litters), - the effect of strain is fixed (we have specific interest in the 2 strains), - model: y_ijk = mu + alpha_i + B_ij + eps_ijk, where B_ij's are assumed i.i.d. N(0,sigma_B^2), and where eps_ijk's are assumed i.i.d. N(0,sigma^2). - type of analysis: hierarchical model with two levels (mouse and litter), - ANOVA table: Source DF F ------------------------------------------- Strains 1 MS(Strain)/MS(Litt) Litters(Strain) 12 MS(Litt)/MSE Error 42 Total 55