NSES Content Standard G 
History and Nature of Science: Nature of science
Grades 5-8, page 171

In areas where active research is being pursued and in which there is not a great deal of experimental or observational evidence and understanding, it is normal for scientists to differ with one another about the interpretation of the evidence or theory being considered. Different scientists might publish conflicting experimental results or might draw different conclusions from the same data. Ideally, scientists acknowledge such conflict and work towards finding evidence that will resolve their disagreement.

Benchmark 1A The Nature of Science: The Scientific World View
Grades 6-8, page 7
When similar investigations give different results, the scientific challenge is to judge whether the differences are trivial or significant, and it often takes further studies to decide. Even with similar results, scientists may wait until an investigation has been repeated many times before accepting the results as correct.

Benchmark 1B The Nature of Science: Scientific Inquiry
Grades 3-5, page 11
Scientists' explanations about what happens in the world come partly from what they observe, partly from what they think. Sometimes scientists have different explanations for the same set of observations. That usually leads to their making more observations to resolve the differences.

Benchmark 12A Habits of Mind: Values and Attitudes
Grades 6-8, page 287
Know that often different explanations can be given for the same evidence, and it is not always possible to tell which one is correct.