What is the effect of increasing sample size on the error rates in a hypothesis test?

Increasing the sample size decreases the chance of a Type II error but does not have any effect on the chance of a Type I error.

In the graph below (which hopefully
illustrates this idea) we consider spinning a coin n times to determine whether
the coin is biased. The red shaded region corresponds with the chance of a Type
I error and the green shaded region corresponds with the chance of a Type II
error **if** the true chance of heads is .60.

Animations that display this:

n=100 -> n=500 then repeat | |

n=100 -> n=500 and back |