front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |review

D = diseased people, and no D healthy. The test can be either positive or negative in either group of people. You want to see it positive in diseased people and negative in the others but it doesn’t always work that way. b in the table above represents false positive results, and c false negatives.