Benchmark 12A
Habits of Mind: Values and Attitudes
Grades 6-8, page 287

Know that hypotheses are valuable, even if they turn out not to be true, if they lead to fruitful investigations.

NSES Content Standard A 
Science as Inquiry: Abilities necessary to do scientific inquiry
Grades 5-8, page 145
Design and conduct a scientific investigation. Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables. They should also develop the ability to clarify their ideas that are influencing and guiding the inquiry, and to understand how those ideas compare with current scientific knowledge. Students can learn to formulate questions, design investigations, execute investigations, interpret data, use evidence to generate explanations, propose alternative explanations, and critique explanations and procedures.