In this applet, we are considering a test for some condition (perhaps we want to diagnoze a disease or administer a drug test).

You imput assumtions regarding the prevalence of the condition and the specificity/sensitivity for a test for the condition.

The outputs are the probabilities that, under the assumptions, given a positive test result you have the condition and that given a negative test result you have the condition.

Try playing around with the sliders -- what happens to our results as a disease gets more prevalent?

This applet was made by Andrew Sanchez for use at Tufts University.