In this process they eliminaate microorganisms until they can identify the group, then genera and finally the speices. The review of taxon characteristics is the main learning activity. Some students will approach the problem by selecting a possible candidate organism. Following the first test which should be a gram stain, students may choose a possible candidate. They then select test that are common to that organism, and exclude all organisms that don't match the test.
Many students run a lot of tests rapidly for their first unknown.
This strategy is usually replaced by a more calculating strategy. Some students are more calculating delibrating for longer periods of time before selecting a test. They usually run few tests to determine their unknowns. This approach requires more time to study and compare the characteristics in the Taxon Reference window.