Binary response variables

Suppose that on each individual we have an observation that takes one of two possible forms. The following are examples:

an electronic component may be defective, or may be nondefective;

a test animal may die from a specified dose of a poison, or may survive;

a subject may give the correct reply in an experimental situation, or may give a wrong reply;

a test specimen may fracture when struck with a standardized blow, or may not;