Mining Data

The Mining data set contains the results of an experiment to determine whether drilling time was faster for wet drilling or dry drilling (Penner and Watts; 1991). Tests were replicated three times for each method at different test holes. There is one observation per five-foot interval for each replication.

The following list describes each variable:

depth

depth of the hole, in feet

driltime

time to drill the last five feet of the current depth, in minutes

method

drilling method, wet or dry

rep

replicate number