Scientific Hypothesis Fundamentals

Scientific Hypothesis

• A scientific hypothesis is a testable, clear statement about an expected outcome in a science experiment.
• It's based on observations and prior knowledge.
• It's written before the experiment to assess if the experiment supports or refutes the hypothesis.
• A well-written hypothesis is easily supported or refuted by experimental results.

Characteristics of a Good Hypothesis

• Testable: Must be able to be proven or disproven through a scientific experiment.
• Clear: Must be specific and unambiguous about what you predict will happen.

How to Develop a Hypothesis

• Step 1: Ask a Question: Focus on specific questions using terms like who, what, when, where, why, or how.
• Step 2: Preliminary Research: Gather information from reliable sources (journals, case studies, observations). Look for conflicting results; acknowledge different viewpoints.
• Step 3: Answer Your Question: Form a conclusion based on your research. For example, you might find evidence that sleep deprivation leads to decreased alertness and therefore, poorer driving performance.
• Step 4: Write Your Hypothesis: Use an "if/then" statement to clearly state the variables and predicted outcome. Example: "If a person experiences more sleep deprivation, then their driving performance will be negatively impacted." The hypothesis must be a statement, not a question.

Examples of Good Hypotheses

• If a person gets 8 hours of sleep, then their memory will improve.
• If teeth are brushed twice daily, then a person is less likely to develop cavities.
• If a plant is exposed to sunlight, then it will grow more than a plant in a dark room.
• If a new battery is used in a car, then the car will get better gas mileage.

Examples of Poor Hypotheses

• "It doesn't matter if you do your homework or not." (Not testable; lacks specific variables)
• "Lightning is caused by ghosts in the sky." (Not testable; relies on unproven concepts)
• "Fertilizer is better for flowers than it is for vegetable plants." (Not testable; uses opinion-based language)
• "Ice cream tastes the best at midnight." (Opinion; not based on testable facts)