3 Mixed Models Without Relationships

Learning Objectives

By the end of this chapter, you will be able to:

Distinguish fixed from random effects and state when each is appropriate
Build Z for a random classification effect
Assemble and solve the MME with a variance ratio α
Contrast BLUE of fixed effects with BLUP of random effects, and explain shrinkage
Reproduce the hand solution with lmer()

Assumes Ch 2.

Chapter in progress

This chapter has not been written yet. The objectives above are the contract it will be written against — they are taken from CHAPTERS.md, which is the outline for the whole book.

Purpose. Introduce Z and random effects with no genetics attached. G = I.

---
title: "Mixed Models Without Relationships"
---

::: {.callout-note icon=false}
## Learning Objectives

By the end of this chapter, you will be able to:

1. **Distinguish** fixed from random effects and state when each is appropriate
2. **Build** **Z** for a random classification effect
3. **Assemble** and solve the MME with a variance ratio α
4. **Contrast** BLUE of fixed effects with BLUP of random effects, and explain shrinkage
5. **Reproduce** the hand solution with `lmer()`
:::

*Assumes Ch 2.*

::: {.callout-warning}
## Chapter in progress

This chapter has not been written yet. The objectives above are the contract it will be written
against — they are taken from `CHAPTERS.md`, which is the outline for the whole book.

**Purpose.** Introduce **Z** and random effects with no genetics attached. **G = I**.
:::