Act like a helpful tutor and exlain me : import tables in randered code14.7. Derive the expected mean squares for a balanced three-stage nested design, assuming that A is fixed and that B and C are random. Obtain formulas for estimating the variance components. Assume the restricted form of the mixed model.
Question:
Act like a helpful tutor and exlain me :
import tables in randered code
14.7. Derive the expected mean squares for a balanced
three-stage nested design, assuming that A is fixed and that B
and C are random. Obtain formulas for estimating the
variance components. Assume the restricted form of the
mixed model.
This is AI generated Response.
Asked by: Umesh
Created at: 2025-08-03 23:36:15
Asked by: Umesh
Created at: 2025-08-03 23:36:15
Final Answer:
Rendered
Raw Text
Did you like this answer?
Let's break down the question step by step and provide a clear, **rendered table** to help you understand a **three-stage nested design** with **expected mean squares** and **variance component estimates**.
---
### **Problem Setup**
- **Three-stage nested design:**
- **A**: Fixed factor (e.g., Treatment)
- **B(A)**: Random factor nested within A (e.g., Batch within Treatment)
- **C(B)**: Random factor nested within B (e.g., Sample within Batch)
- The model (for observation \( y_{ijkl} \)) is:
\[
y_{ijkl} = \mu + \alpha_i + \beta_{j(i)} + \gamma_{k(j(i))} + \epsilon_{l(k(j(i)))}
\]
- \( \alpha_i \): Fixed effect of level \(i\) of A
- \( \beta_{j(i)} \): Random effect of level \(j\) of B within A
- \( \gamma_{k(j(i))} \): Random effect of level \(k\) of C within B
- \( \epsilon_{l(k(j(i)))} \): Random error
---
### **Balance and Replication**
Suppose:
- \(a\) levels of A
- \(b\) levels of B within each A
- \(c\) levels of C within each B
- \(n\) replicates within each C
---
## **Expected Mean Squares (EMS) Table**
| Source | Degrees of Freedom | Expected Mean Square |
|--------------------------|-------------------|---------------------------------------------|
| A | \(a-1\) | \(\sigma^2_e + n\sigma^2_\gamma + nc\sigma^2_\beta + ncb \cdot \text{(A effect)}\) |
| B (A) | \(a(b-1)\) | \(\sigma^2_e + n\sigma^2_\gamma + nc\sigma^2_\beta \) |
| C (B) | \(ab(c-1)\) | \(\sigma^2_e + n\sigma^2_\gamma \) |
| Error | \(abc(n-1)\) | \(\sigma^2_e\) |
Where:
- \(\sigma^2_\beta\): Variance component for B(A)
- \(\sigma^2_\gamma\): Variance component for C(B)
- \(\sigma^2_e\): Error variance
---
## **Variance Component Estimates**
You estimate variance components by equating observed mean squares to their expectations (solving for each variance):
### **Formulas:**
\[
\begin{align*}
\hat{\sigma}^2_e &= MS_{Error} \\
\hat{\sigma}^2_\gamma &= \frac{MS_{C(B)} - MS_{Error}}{n} \\
\hat{\sigma}^2_\beta &= \frac{MS_{B(A)} - MS_{C(B)}}{nc} \\
\end{align*}
\]
- For A (fixed effect), you do **not** estimate a variance component (since it's fixed).
---
## **Summary Table (Rendered)**
| Source | D.F. | Expected Mean Square | Variance Estimate Formula |
|----------|--------------|-------------------------------------------|--------------------------------------------|
| A | \(a-1\) | \(\sigma^2_e + n\sigma^2_\gamma + nc\sigma^2_\beta + ncb \cdot (\text{A effect})\) | N/A (Fixed) |
| B(A) | \(a(b-1)\) | \(\sigma^2_e + n\sigma^2_\gamma + nc\sigma^2_\beta\) | \(\hat{\sigma}^2_\beta = \frac{MS_{B(A)} - MS_{C(B)}}{nc}\) |
| C(B) | \(ab(c-1)\) | \(\sigma^2_e + n\sigma^2_\gamma\) | \(\hat{\sigma}^2_\gamma = \frac{MS_{C(B)} - MS_{Error}}{n}\) |
| Error | \(abc(n-1)\) | \(\sigma^2_e\) | \(\hat{\sigma}^2_e = MS_{Error}\) |
---
### **Restricted Model**
The "restricted form" means that the random effects have mean zero and are independent.
---
### **Summary**
1. **Write the model** with fixed/random effects.
2. **Build the EMS table** as above.
3. **Use the mean squares** from your ANOVA table to estimate variance components with the given formulas.
If you need an **example with numbers** or a **step-by-step calculation**, just ask!
📢 Instructions:
- Ask anything relatd to above question only.
- For new Question goto :
VIPSolutions