Spearman Correlation 6Dddd3
1. **Problem Statement:** Calculate Spearman's rank correlation coefficient to assess the consistency between employee performance scores and peer review rankings.
2. **Formula:** Spearman's rank correlation coefficient $\rho$ is given by:
$$\rho = 1 - \frac{6 \sum d_i^2}{n(n^2 - 1)}$$
where $d_i$ is the difference between the ranks of each pair and $n$ is the number of pairs.
3. **Step 1: Assign ranks to Performance Scores:**
Performance Scores: 90, 76, 84, 70, 88, 82
Ranks (highest score rank 1):
- 90: 1
- 88: 2
- 84: 3
- 82: 4
- 76: 5
- 70: 6
4. **Step 2: Given Peer Review Ranks:**
1, 3, 2, 6, 4, 5
5. **Step 3: Calculate differences $d_i$ and $d_i^2$:**
| Employee | Performance Rank | Peer Review Rank | $d_i$ = Perf Rank - Peer Rank | $d_i^2$ |
|----------|------------------|------------------|------------------------------|---------|
| 1 | 1 | 1 | 0 | 0 |
| 2 | 5 | 3 | 2 | 4 |
| 3 | 3 | 2 | 1 | 1 |
| 4 | 6 | 6 | 0 | 0 |
| 5 | 2 | 4 | -2 | 4 |
| 6 | 4 | 5 | -1 | 1 |
Sum of $d_i^2 = 0 + 4 + 1 + 0 + 4 + 1 = 10$
6. **Step 4: Calculate $\rho$:**
Number of pairs $n = 6$
$$\rho = 1 - \frac{6 \times 10}{6(6^2 - 1)} = 1 - \frac{60}{6(36 - 1)} = 1 - \frac{60}{6 \times 35} = 1 - \frac{60}{210} = 1 - \frac{2}{7} = \frac{5}{7} \approx 0.714$$
7. **Interpretation:**
A Spearman's rank correlation coefficient of approximately 0.714 indicates a strong positive correlation between performance scores and peer review rankings, suggesting good consistency.
Final answer: $\boxed{0.714}$