A chemical engineer believes that the time of reaction for a chemical process is a function of the type of catalyst employed. For four catalysts under investigation, the experiment consists of selecting a batch of raw material, loading the pilot plant, applying each catalyst in a separate run of the pilot plant and observing the reaction time. Believing that variations in the batches of raw material may affect the catalysts' performance, the engineer decides to use the batches of raw material as blocks, although each block is large enough to permit only three catalysts to be run. The data is shown below.
Source: Montgomery, D.C. (2001). The Design and Analysis of Experiments. John Wiley & Sons: New York.
Table 19: Catalyst Data
| TRMT | BLOCK (Raw Material Batch) | |||
|---|---|---|---|---|
| Catalyst | 1 | 2 | 3 | 4 |
| 1 | 73 | 74 | -- | 71 |
| 2 | -- | 75 | 67 | 72 |
| 3 | 73 | 75 | 68 | -- |
| 4 | 75 | -- | 72 | 75 |
Questions:
Keywords: Balanced incomplete block design (BIBD), Adjusted sums of squares (Type III SS)