1. General Full Factorial Design
Dedy Sugiarto

2. Case 2 : Time to boil water experiment
For example, we may want to investigate the influence of pan size and cover on the time in minute to boil water. We use general full factorial design and completely randomize design or without blocking of experimental unit. Single. There are two-level for each factor and 3 replications for each combination. Dimensions of small pan is 14 cm for diameter and 10 cm for height. Dimensions of medium pan is 18 cm for diameter and 11 cm for height. Volume of water is 600 ml.

3. Randomization using Minitab :
RunOrder
pan size
cover
time (minutes) 1
medium no 2
small
yes 3 4 5 6 7 8 9 10 11 12

4. Picture 5. Medium pan with cover on
Picture 4. Small pan, medium
pan and glass
cover
Picture 5. Medium pan with cover on
stove

5. The results of experiment :
RunOrder
pan size
cover
time (minutes) 1
medium no
3.92 2
small
yes
3.07 3
3.00 4
3.53 5
3.63 6
3.83 7
3.20 8
3.22 9
3.75 10
3.98 11
3.50 12
3.60

6. Minitab Output :
General Linear Model: time (minutes) versus pan size, cover
Factor Type Levels Values
pan size fixed small, medium
cover fixed yes, no
Analysis of Variance for time (minutes), using Adjusted SS for Tests
Source DF Seq SS Adj SS Adj MS F P
pan size
cover
pan size*cover
Error
Total
S = R-Sq = 59.70% R-Sq(adj) = 44.58%
Unusual Observations for time (minutes)
time
Obs (minutes) Fit SE Fit Residual St Resid R
R denotes an observation with a large standardized residu

8. Interpreting the Results :
The small p-values for the pan size (p = 0.058) and cover (p = 0.093) that lower than α (0.10) suggest there is enough significant effect of pan size and cover on time to boil water. Interaction of pan size and cover is not significant. Mean plot of rensponse suggests that small and cover (yes) give lower time to boil water .