Stratum

1

2

3

4

5

6

7

8


X
_{
1
}

0

1

0

0

1

1

0

1

X
_{
2
}

0

0

1

0

1

0

1

1

X
_{
3
}

0

0

0

1

0

1

1

1

Probability

0.300

0.176

0.563

0.391

0.563

0.096

0.794

0.836

 We define 8 strata based on combinations of 3 binary predictors X_{1}, X_{2} and X_{3}. The conditional probability of success of the outcome Y for each of these strata is given in the table. Outcomes Y are simulated within each stratum using a binomial random number generator with probability of success given in the table.