Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

Obs | treat | richness | total | algae | y
--- | --- | --- | --- | --- | ---
1 | Control | 8 | 78 | 1 | 0.10017
2 | Control | 5 | 84 | 7 | 0.26776
3 | Control | 10 | 115 | 45 | 0.73531
4 | Control | 7 | 200 | 100 | 1.57080
5 | Control | 6 | 72 | 20 | 0.46365
6 | Low | 8 | 73 | 15 | 0.39770
7 | Low | 7 | 124 | 70 | 0.99116
8 | Low | 8 | 116 | 50 | 0.78540
9 | Low | 8 | 92 | 5 | 0.22551
10 | Low | 7 | 138 | 60 | 0.88608
11 | Medium | 7 | 124 | 85 | 1.17310
12 | Medium | 8 | 116 | 80 | 1.10715
13 | Medium | 8 | 145 | 60 | 0.88608
14 | Medium | 6 | 154 | 100 | 1.57080
15 | Medium | 7 | 129 | 90 | 1.24905
16 | High | 6 | 134 | 95 | 1.34528
17 | High | 7 | 138 | 95 | 1.34528
18 | High | 8 | 103 | 70 | 0.99116
19 | High | 8 | 119 | 75 | 1.04720
20 | High | 6 | 132 | 80 | 1.10715
21 | VeryHigh | 6 | 148 | 95 | 1.34528
22 | VeryHigh | 5 | 134 | 95 | 1.34528
23 | VeryHigh | 5 | 119 | 100 | 1.57080
24 | VeryHigh | 5 | 117 | 90 | 1.24905
25 | VeryHigh | 5 | 129 | 80 | 1.10715

Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

The GLM Procedure

Class Level Information
Class | Levels | Values
--- | --- | ---
treat | 5 | Control High Low Medium VeryHigh

Number of Observations Read | 25
Number of Observations Used | 25

Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

The GLM Procedure

Dependent Variable: y

Source | DF | Sum of Squares | Mean Square | F Value | Pr > F
--- | --- | --- | --- | --- | ---
Model | 4 | 2.13816313 | 0.53454078 | 4.76 | 0.0073
Error | 20 | 2.24444069 | 0.11222203 |  |
Corrected Total | 24 | 4.38260382 |  |  |

R-Square | Coeff Var | Root MSE | y Mean
--- | --- | --- | ---
0.487875 | 33.68371 | 0.334996 | 0.994533

Source | DF | Type I SS | Mean Square | F Value | Pr > F
--- | --- | --- | --- | --- | ---
treat | 4 | 2.13816313 | 0.53454078 | 4.76 | 0.0073

Source | DF | Type III SS | Mean Square | F Value | Pr > F
--- | --- | --- | --- | --- | ---
treat | 4 | 2.13816313 | 0.53454078 | 4.76 | 0.0073

Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

The GLM Procedure

Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

The GLM Procedure

t Tests (LSD) for y

Note:This test controls the Type I comparisonwise error rate, not the experimentwise error rate.

Alpha | 0.05
Error Degrees of Freedom | 20
Error Mean Square | 0.112222
Critical Value of t | 2.08596
Least Significant Difference | 0.442

Comparisons significant at the 0.05 level are indicated by ***.
treat Comparison | Difference Between Means | 95% Confidence Limits |
--- | --- | --- | ---
VeryHigh - Medium | 0.1263 | -0.3157 | 0.5682 |
VeryHigh - High | 0.1563 | -0.2857 | 0.5983 |
VeryHigh - Low | 0.6663 | 0.2244 | 1.1083 | ***
VeryHigh - Control | 0.6960 | 0.2540 | 1.1379 | ***
Medium - VeryHigh | -0.1263 | -0.5682 | 0.3157 |
Medium - High | 0.0300 | -0.4119 | 0.4720 |
Medium - Low | 0.5401 | 0.0981 | 0.9820 | ***
Medium - Control | 0.5697 | 0.1277 | 1.0116 | ***
High - VeryHigh | -0.1563 | -0.5983 | 0.2857 |
High - Medium | -0.0300 | -0.4720 | 0.4119 |
High - Low | 0.5100 | 0.0681 | 0.9520 | ***
High - Control | 0.5397 | 0.0977 | 0.9816 | ***
Low - VeryHigh | -0.6663 | -1.1083 | -0.2244 | ***
Low - Medium | -0.5401 | -0.9820 | -0.0981 | ***
Low - High | -0.5100 | -0.9520 | -0.0681 | ***
Low - Control | 0.0296 | -0.4123 | 0.4716 |
Control - VeryHigh | -0.6960 | -1.1379 | -0.2540 | ***
Control - Medium | -0.5697 | -1.0116 | -0.1277 | ***
Control - High | -0.5397 | -0.9816 | -0.0977 | ***
Control - Low | -0.0296 | -0.4716 | 0.4123 |

Multiple comparisons for algae cover

Data from Kneitel and Lessin (2010)

The GLM Procedure

t Tests (LSD) for y

Note:This test controls the Type I comparisonwise error rate, not the experimentwise error rate.

Alpha | 0.05
Error Degrees of Freedom | 20
Error Mean Square | 0.112222
Critical Value of t | 2.08596
Least Significant Difference | 0.442