NSES Content Standard A  Science as Inquiry: Abilities necessary to do scientific inquiry  Grades K-4, page 122  Use data to construct a reasonable explanation. This aspect of the standard emphasizes the students' thinking as they use data to formulate explanations. Even at the earliest grade levels, students should learn what constitutes evidence and judge the merits or strength of the data and information that will be used to make explanations. After students propose an explanation, they will appeal to the knowledge and evidence they obtained to support their explanations. Students should check their explanations against scientific knowledge, experiences, and observations of others.

 
Benchmark 1B The Nature of Science: Scientific Inquiry
Grades 3-5, page 11
Results of scientific investigations are seldom exactly the same, but if the differences are large, it is important to try to figure out why. One reason for following directions carefully and for keeping records of one's work is to provide information on what might have caused the differences.

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 1B The Nature of Science: Scientific Inquiry
Grades 3-5, page 11
Scientists do not pay much attention to claims about how something they know about works unless the claims are backed up with evidence that can be confirmed and with a logical argument.

Benchmark 12A Habits of Mind: Values and Attitudes
Grades 3-5, page 286
Offer reasons for their findings and consider reasons suggested by others.

Benchmark 12E Habits of Mind: Critical-Response Skills
Grades K-2, page 298
Ask "How do you know?" in appropriate situations and attempt reasonable answers when others ask them the same question.

Benchmark 12E Habits of Mind: Critical-Response Skills
Grades 3-5, page 299
Buttress their statements with facts found in books, articles, and databases, and identify the sources used and expect others to do the same.

Benchmark 12E Habits of Mind: Critical-Response Skills
Grades 3-5, page 299
Seek better reasons for believing something than "Everybody knows that . . ." or "I just know" and discount such reasons when given by others.