NSES Content Standard A 
Science as Inquiry: Understanding about scientific inquiry
Grades 9-12, page 175

Scientists conduct investigations for a wide variety of reasons. For example, they may want to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.

Benchmark 1B The Nature of Science: Scientific Inquiry
Grades 9-12, page 13
Investigations are conducted for different reasons, including to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.