In the random effects model, both factors are declared as random factors. This recipe looks at a study on taste from a panel of professional taste testers. Different batches of a food product are tested to check the consistency of taste. Each appraiser tastes each batch twice. This way we can observe the consistency of scores from within the appraiser.
As the product is a selection of batches from a much larger population of batches, the samples represent a random selection from all product batches. The taste testers are a sample of appraisers from a group of tasters, representing a random selection as well; we will use the appraiser as a random factor to represent the variation across appraisers.
The scores are a mean figure from four attributes: taste, aroma, texture, and appearance.
The data will be provided later to type into Minitab; for ease of entry, it is set out as a table. We will stack this into columns to run the general linear model with both factors...