If you would rather not install the CDF player, you can try to SageMath verison that does not require you to install anything.

If using Chrome, download and open separately by clicking here.

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 Sánchez for use at Tufts University.