The Scientific Method
Steps that scientists use to answer questions and solve problems Steps that scientists use to answer questions and solve problems Steps may be used in a different order, skipped, or repeated Steps may be used in a different order, skipped, or repeated
The Steps
1. Ask a Question or Find a Problem Observations often lead to questions or problems Observations often lead to questions or problems Will adding fertilizer make a plant grow taller? Will adding fertilizer make a plant grow taller?
2. Form a Hypothesis A possible explanation or answer to a question Must be testable Must be testable If plants are fertilized more, then they will grow taller If plants are fertilized more, then they will grow taller
3. Test the Hypothesis (Procedure) A controlled experiment has a control group and an experimental group A controlled experiment has a control group and an experimental group The basic idea is to change only one factor – the variable The basic idea is to change only one factor – the variable
A Control A Control is a standard used for comparison in an experiment. A Control is a standard used for comparison in an experiment. The plant without the fertilizer The plant without the fertilizer
The Experimental Group Has the variable. The effect of this variable is what is tested. Has the variable. The effect of this variable is what is tested. Variable = the fertilizer Variable = the fertilizer The experimental group = The plant with the fertilizer The experimental group = The plant with the fertilizer
4. Analyze the Results Collect and record data – info acquired by experimentation Collect and record data – info acquired by experimentation Calculations, tables, and graphs are used Calculations, tables, and graphs are used The plant with the fertilizer grew 1.5 cm taller in 1 week The plant with the fertilizer grew 1.5 cm taller in 1 week
Draw Conclusions Did your results support your hypothesis or not? Did your results support your hypothesis or not? Do you need more information? Do you need more information? The fertilizer made the plant grow taller The fertilizer made the plant grow taller Communicate results so they can be verified and repeated. Communicate results so they can be verified and repeated.
Observation: Any piece of information learned directly through the senses Any piece of information learned directly through the senses Explanations we use to make sense of our observations. Inferences are not final explanations for observations, there may be many logical inferences for one observation. Explanations we use to make sense of our observations. Inferences are not final explanations for observations, there may be many logical inferences for one observation. Inference: