Benchmark 12C
Habits of Mind: Manipulation and Observation
Grades 3-5, page 293

Keep a notebook that describes observations made, carefully distinguishes actual observations from ideas and speculations about what was observed, and is understandable weeks or months later.
 

NSES Content Standard A 
Science as Inquiry: Abilities necessary to do scientific inquiry
Grades 5-8, page 145
Develop descriptions, explanations, predictions, and models using evidence. Students should base their explanation on what they observed, and as they develop cognitive skills, they should be able to differentiate explanation from description--providing causes for effects and establishing relationships based on evidence and logical argument. This standard requires a subject matter knowledge base so the students can effectively conduct investigations, because developing explanations establishes connections between the content of science and the contexts within which students develop new knowledge.