Vocabulary1. observation- information gained by using the senses.2. Inference- conclusion based on evidence of premises.3. Hypothesis- an explanation that is based on prior research or observation and that can be tested.
What Are Scientific Methods?• Scientific Method- A series of steps followed to solve problems.• The steps are not always followed in the same order.
What are the steps in the scientific method?• Ask a question• Form a Hypothesis• Test the hypothesis• Analyze the results• Draw a conclusion• Communicate results
Ask a question• Scientists often ask questions after observation.• Observation- The process of obtaining information by using the senses.• Example- What is the effect of temperature on the speed a worm travels?
Hypothesis• Hypothesis- An idea or explanation that is based on prior scientific research or observations and that can be tested.• Sometimes called an educated guess.
Hypothesis continued• Usually stated as an if then sentence.• Example- If temperature increases, then the speed a worm travels will increase.
Test the hypothesis• Scientists test the hypothesis by gathering data.• Data- any pieces of information acquired through observation or experimentation.• Sometimes a controlled experiment is used.
Test hypothesis continued• Controlled experiments test only one factor at a time.• The one factor that is changed is called the variable.
• The manipulated variable is the variable that the scientist purposely changes.• If I am testing the effect of temperature on earthworm travel speed then the manipulated variable is the temperature.
• The responding variable is the variable that changes as a result of the manipulated variable.• In the worm example the responding variable is the speed that the worm travels.
Test hypothesis continued again• Sometimes scientists test without an experiment by observing and collecting data.• Example- The scientist might observe birds to see what type of tree they nest in.
Analyze the results• To analyze results scientists often use tables and graphs.• Example- Putting all of the measurements and into graphs and charts.
Draw a conclusion• Decide whether the data supports the hypothesis or not.• If it does not support the hypothesis scientists may repeat the experiment to check for mistakes or ask a new question and form a new hypothesis.• Example- From the data it has been discovered that as temperature rises earthworm speed increases. One might wonder if the same is true in other types of worms.
Communicate results• Scientists share results by writing reports or giving talks.• Science depends on sharing.• It allows others to repeat the experiment.• Openness and replication of experimental results keeps a scientists believability.