Modified Method on Confidence Intervals for Variance in One-Factor Components-of-Variance Model

The confidence intervals for σ²A are given in various forms by many authors in onefactor components-of-variance model y ij = μ+ A i + e ij . In this model, Howe’s(1974) method confidence intervals for σ²A are given by an asymptotic confidence intervals. By the simulation results of this confidence coefficients are not fit exactly to 1 -α/2 confidence coefficients. And this confidence coefficients are close to 1 -α/2 when J is large. In this J is too large to use in the simulation. Thus, we would like to give one of the modified Howe’s(1974) method confidence intervals for σ²A in one-factor components-of-variance model. By the simulation results of this modified confidence coefficients are better than those obtained by using Howe’s(1974) method confidence coefficients, and we can simulate when J is small.