The Nature of Science

The Nature of ScienceWhat is Science?How do scientists work?

Goal of ScienceTo understand the world around usEX. Does life appear from non-living matter?To explain events by making predictionsEX. Life doesnt appear from non-living matter.To investigate predictionsEX. Setting up an experiment to see if life comes from non-living matter, or from living thingsVideo: How scientists work

How could you use the scientific method in your daily life?One example to make a friend: http://www.youtube.com/watch?v=k0xgjUhEG3U

Observations- Gathering evidenceIt all starts here!Using 5 SENSES to gather informationQuantitative:Observation using numbers and measurementEX. Twenty-four people have iPhones in this classroom.Can you make a quantitative observation in this classroom?# of desks, students, length of desk, etc..Qualitative:Observation that doesnt involve numbersEX. I dont see people get flustered using their iPhones.Can you make a qualitative observation in this classroom?The lab tables are black, walls are white, etc..

Inferences- Interpreting the EvidenceINTERPRETATION based on observation and prior knowledge or experienceEX. iPhones are the easiest smartphones to use.Observation = Most smartphones I see are iPhones.Prior knowledge = My iPhone is easy to use.Can you make an inference about one of your observations?The lab tables are black because they are made of coal. Observation = lab tables are blackPrior knowledge = coal is blackHypothesis- Explaining the EvidenceThe answer to a BURNING QUESTION!Only useful if it can be tested!Evidence must be gathered and tested.Example: Question = Does ozone gas affect the growth of plants?How would we measure growth?Height, number of leaves, number of flowersHypothesis = If plants are exposed to ozone gas, then they will show more growth.We now must set up a controlled experiment to test our hypothesis!!!!What is the process called that scientists use?SCIENTIFIC METHOD!

The Scientific MethodState the problem or write a question(the burning question)Form a hypothesis (answer to burning question based on observations and prior knowledge)Design a controlled experimentOnly ONE variable is tested at a timeAll other variables must be kept the SAMECollect organized dataAnalyze dataForm a conclusion (Was your hypothesis correct?)Peer evaluation (Can your experiment be retested and always get same results?)LETS SEE HOW IT WORKS!The ScenarioA group of scientists would like to know the affects of ozone on plant life.They set up several mini ecosystems in separate domes to conduct their experiment.Each dome receives a different amount of ozone and one dome receives none.Setting up a Controlled Experiment

Important Terms- What are variablesVariable:Things that can be manipulated or changed by scientist during experimentA controlled experiment tests ONE variable, while the others must stay the sameExamples from video clip:Sunlight, water, type of soil, type of plant, ozone gasIndependent Variable: Manipulated (CHANGED) by scientistVariable that is being testedI am testing INDEPENDENTExample from video clip:Ozone gas is being tested Dependent Variable: Changes in response to the tested variableThe things the scientist is measuringDEPENDENT-DATA, DEPENDENT-DATA, DEPENDENT-DATAExample from video clip:Plant height, leaf count, rate of photosynthesis

Important Terms- What makes it a controlled experiment?Controlled Variables:Things that must be kept constant during experimentIf altered, can affect results and be used to show error in experiment.Examples from video clip:Sunlight, amount of water, type of soil, type of plantControl Group:Experimental setup that does not receive the variable that is being testedAll other groups are compared with the results of this group to see if there is any change to the test subjectOften called the standard for comparisonExample from video clip:Dome without ozone gasNO ozone gas

Lets practice!!