The abrasion
data frame has 16 rows and 4 columns. Four materials
were fed into a wear testing machine and the amount of wear recorded. Four
samples could be processed at the same time and the position of these
samples may be important. A Latin square design was used.
This data frame contains the following columns:
The run number 1-4
The position number 1-4
The material A-D
The wear measured loss of weight in 0.1mm over testing period