Benchmark 1B
The Nature of Science: Scientific Inquiry
Grades K-2, page 10

People can often learn about things around them by just observing those things carefully, but sometimes they can learn more by doing something to the things and noting what happens.
 

NSES Content Standard A 
Science as Inquiry: Abilities necessary to do scientific inquiry 
Grades K-4, page 122 
Ask a question about objects, organisms, and events in the environment. This aspect of the standard emphasizes students asking questions that they can answer with scientific knowledge, combined with their own observations. Students should answer their questions by seeking information from reliable sources of scientific information and from their own observations and investigations. 

NSES Content Standard A
Science as Inquiry: Abilities necessary to do scientific inquiry 
Grades K-4, page 122 
Plan and conduct a simple investigation. In the earliest years, investigations are largely based on systematic observations. As students develop, they may design and conduct simple experiments to answer questions. The idea of a fair test is possible for many students to consider by fourth grade. 

NSES Content Standard A
Science as Inquiry: Understanding about scientific inquiry 
Grades K-4, page 123 
Scientists use different kinds of investigations depending on the questions they are trying to answer. Types of investigations include describing objects, events, and organisms, classifying them and doing a fair test (experimenting).