• 6-8: 1A/M2. Scientific knowledge is subject to modification as new information challenges prevailing theories and as a new theory leads to looking at old observations in a new way.
• 6-8: 1A/M3. Some scientific knowledge is very old and yet is still applicable today.

• 3-5: 1B/E1. Scientific investigations may take many different forms, including observing what things are like or what is happening somewhere, collecting specimens for analysis, and doing experiments.
• 3-5: 1B/E4. 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, along with a logical argument.
• 9-12: 1B/H1. Investigations are conducted for different reasons, including to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare theories.
• 9-12: 1B/H2. Hypotheses are widely used in science for choosing what data to pay attention to and what additional data to seek, and for guiding the interpretation of the data (both new and previously available).

• 3-5: 1C/E1. Science is an adventure that people everywhere can take part in, as they have for many centuries.
• 3-5: 1C/E2. Clear communication is an essential part of doing science. It enables scientists to inform others about their work, expose their ideas to criticism by other scientists, and stay informed about scientific discoveries around the world.
• 6-8: 1C/M1. Important contributions to the advancement of science, mathematics, and technology have been made by different kinds of people, in different cultures, at different times.
• 6-8: 1C/M7. Accurate record-keeping, openness, and replication are essential for maintaining an investigator's credibility with other scientists and society.
• 9-12: 1C/H1. The early Egyptian, Greek, Chinese, Hindu, and Arabic cultures are responsible for many scientific and mathematical ideas and technological inventions. Modern science is based on traditions of thought that came together in Europe about 500 years ago. People from all cultures now contribute to that tradition.

• 1B (6-8) #1.  Scientists differ greatly in what phenomena they study and how they go about their work. Although there is no fixed set of steps that all scientists follow, scientific investigations usually involve the collection of relevant evidence, the use of logical reasoning, and the application of imagination in devising hypotheses and explanations to make sense of the collected evidence.
• 1B (6-8) #2.  If more than one variable changes at the same time in an experiment, the outcome of the experiment may not be clearly attributable to any one of the variables. It may not always be possible to prevent outside variables from influencing the outcome of an investigation (or even to identify all of the variables), but collaboration among investigators can often lead to research designs that are able to deal with such situations.
• 1B (6-8) #3.  What people expect to observe often affects what they actually do observe. Strong beliefs about what should happen in particular circumstances can prevent them from detecting other results. Scientists know about this danger to objectivity and take steps to try and avoid it when designing investigations and examining data. One safeguard is to have different investigators conduct independent studies of the same questions.

Want to get your students genuinely excited about how science is practiced by real people? The Physics Front editors highly recommend this set of modules for secondary science classrooms. The unit consists of 15 sections, including how to design a good experiment, manipulate variables, recognize bias, collect and interpret data, error/uncertainty, and how to clearly communicate findings.

• Physical Sciences K-8 The Scientific Process Unit
• Physics First The Scientific Process Unit
• Conceptual Physics The Scientific Process Unit
• Algebra-Based Physics The Scientific Process Unit
• AP/Calculus-Based Physics The Scientific Process Unit