1 Scientific Questions and the Scientific Method
Learn how scientists frame answerable questions, develop hypotheses and predictions, gather evidence, and adapt investigations as they learn.
Forming testable questions
Science begins with curiosity about the natural world. A useful investigation turns an observation or idea into a question that can be addressed with .
A is specific enough that observations or measurements could help answer it. “Why are plants interesting?” is too broad to investigate directly. By contrast, “Do bean seedlings exposed to more hours of light per day grow taller after 14 days?” identifies what will be compared and what could be collected.
A strong question is also feasible to investigate and does not assume its answer. Some questions are answered through experiments; others call for observations, comparisons, or analysis of existing data. The method should fit the question.
Developing hypotheses and predictions
A is a proposed explanation or answer that can be evaluated using . It should be clear enough that an investigation could show whether its predictions are supported. For the seedling question, one is: “More daily light increases bean seedling growth because light provides energy for photosynthesis.”
A states an expected observation if the is correct. For example: “If seedlings receive more hours of light each day, then their average height after 14 days will be greater.” Predictions help investigators decide what to collect.
A is not simply a guess. It should draw on observations or existing knowledge while remaining open to testing and revision.
The as a flexible process
The is a flexible process, not a fixed recipe that every scientist follows in exactly the same order. Investigations commonly involve connected practices:
Observe and ask. Notice a pattern or problem and frame a focused, .
Explore what is known. Use relevant background information to refine the question and guide an investigation.
Develop a and . State a possible explanation and what you would expect to observe if it is supported.
Gather . Choose an appropriate experiment, observation, or other method, and record carefully.
Interpret and communicate. Compare the with the , explain the reasoning, and share the methods and findings.
Reconsider and continue. Results may support the , fail to support it, or be inconclusive. Investigators may revise the explanation, improve the method, or ask a new question.
These practices do not always happen in order. Results can lead scientists to change a question or , and one investigation may prompt several more.
Interpreting and revising investigations
that agrees with a can support a , but it does not prove that the is certainly true. that does not agree may challenge the , or it may reveal that the method, measurements, or assumptions need review.
In either case, conclusions should match what the can actually show. Scientists examine their reasoning, communicate methods and findings, and may revise or extend their work as needed.