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.