© John Wiley & Sons, Inc.

FIGURE 23-1: Bending a straight line into different shapes by raising each point on the line to some power: h.

To understand the flex, look at what happens when you raise this straight line to various powers, which

we refer to as h and illustrate in Figure 23-1b:

Squaring: If you set h = 2, the y value for every point on the line always comes out smaller,

because they are always less than 1. For example,

is 0.64.

Taking the square root: If we set h = 0.05, the y value of every point on the line becomes larger.

For example, the square root of 0.25 is 0.5.

Notice in Figure 23-1b, both

and

remain 1, and

and

both remain 0, so those two ends of

the line don’t change.

Does the same trick work for a survival curve that doesn’t follow any particular algebraic formula?

Yes, it does! Look at Figure 23-2.

© John Wiley & Sons, Inc.

FIGURE 23-2: Raising to a power works for survival curves, too.

Here are some important points about Figure 23-2: