Scientific Method PDF

Scientific Method  Where do experiments begin? A scientist notices something in their natural world gathered through his/her senses An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails  Experiment Va...

Scientific Method  Where do experiments begin? A scientist notices something in their natural world gathered through his/her senses An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails  Experiment Variable – something that is changed or will change based on something else * A good experiment only tests one variable at a time, so we are able to state that our results are because of that one variable  The Control Variable(s) All factors are kept constant Controls are not being tested, simply used for comparison  Other Variables Independent variable:The factor that you change is known as the. The cause. Dependent variable:The factor that is measured or observed is called the. The result  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. Which are the independent and dependent variables?  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. 2. It has been determined that too much time on their phone may keep a student from doing their science homework. An experiment was set up to test this. Palram spends 3 hours on his phone each night after school; Kriti spends 5 hours; and Bryan only spends 1 hour. After their Unit TEST, their scores were compared and recorded INDEPENDENT variable = Dependent variable = CONTROL variable = 3. Does eating candy affect the number of cavities a person will have? Vanisha wanted to find out! She had her friend eat different amounts of candy for one year. She asked her friend, after their dentist appointment, how many cavities they had. Independent Dependent Control 4. Four sailboats were cruising down the river. Each boat had a sail that was different size. Does the speed of the boat depend on the size of the sail? The speed of each boat was recorded in order to determine if the sail size had an affect on the speed Independent Dependent Control One more thing… it is best to make several trials with each independent variable.  Hypothesis Predicts an outcome Predicts a specific relationships between the variables. Must be able to be tested Sometimes written as If…Then… statements Eg. If there is some pollution in the water (independent variable), then salamanders tails grow curved (dependent variable)  Materials and Procedure Materials: Lists what equipment will be used Procedure: Explains how to complete the lab Include detailed measurements Written as steps (1…2…) Written in past tense  Observations Explains how the dependent variable changes due to the independent variable Usually included in a table Needs to include units Uses scientific terminology  Data Results of the experiment May be quantitative (numbers) or qualitative (descriptive) Should be organized into charts, tables, and/or graphs  Analysis Discusses the importance of results Connects to real world events Should be organized into charts, tables, and/or graphs  Conclusion The answer to the hypothesis based on the data obtained from the experiment Includes some analysis and discussion on why the results might have occurred In order to verify the results, experiments must be retested.