Scientific Method

Steps in the Scientific Method Problem/Question Observation/Research Hypothesis Experiment Collect & Analyze Data Conclusion Retest/Apply the results

Steps in the Scientific Method _________________

Problem/Question All good scientific inquiry begins with a problem or a question about a topic. This problem can be solved through experimentation.

Observations Gathered through your senses A scientist notices something in their natural world Often called research (learning about problem)

Observations An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails

Hypothesis A possible solution to the problem. Must be testable Often written as If…Then… statements Based on relationship between independent and dependant variables.

Hypothesis An example of a hypothesis might be: The salamanders have curved tails due to a pollutant in the moist soil where they live.

Experiment A materials list is created A detailed procedure is developed and followed. Data is collected and measured

Analysis Analyze your data and results, confirm by retesting. Modify the procedure if needed.

Conclusion Conclusion: includes a statement that either accepts or rejects the hypothesis. As conclusion is written, include any data tables, charts, graphs and photographs

Conclusion It is usually the answer to the hypothesis based on the data obtained from the experiment If needed apply the answer to solve the problem.

Scientific Experiments Follow Rules An experimenter changes one factor and observes or measures what happens.

Important vocabulary

A Variable Variable – factor in the experiment that is being changed, watched, or manipulated. 3 types

The Control Variable control variables – factors that are kept constant so that they do not effect the outcome. NOT tested Are use for comparison

Other Variables The factor that is changed or manipulated is known as the independent variable. (iv) The factor that is measured or observed is called the dependent variable. (it changes because of iv)

Example of Controls & Variables For example, suppose you want to figure out the fastest route to walk home from school. You will try several different routes and time how long it takes you to get home by each one. Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

What are the Variables in Your Experiment? Varying the route is the independent variable The time it takes is the dependent variable Keeping the same walker throughout makes the walker a control variable.

It is best to make several trials with each independent variable.

A valid experiment will only have ONE variable tested! Is repeatable by anyone Has detailed step by step procedure Has precise materials list

Data Results of the experiment May be quantitative (numbers) or qualitative other types Must be organized into charts, tables, or graphs

In order to verify the results, experiments must be retested.