SCIENCE!! And the Scientific Method

Science I. -ology….. study of II. Science – Study of universe and how it works A. must be based on a controlled experiment III. Pseudoscience – fake science A. may have data, graphs, calculations B. NO controlled experiments

IV. Parts of a Controlled Experiment A. Experimental Set-up: includes the thing you are testing B. Control Set-up: what you compare to 1. leave out the thing you are testing 2. like normal 3. starting point you choose

V. Variables in Controlled Experiments A. Independent Variable – not dependent on how experiment goes 1. selected by scientist 2. can put in data table before starting exp. 3. x-axis of graph B. Dependent Variable- 1. measured / recorded by scientist 2. y-axis of graph

C. Controlled Variables – things kept the same between experimental set-up and control set-up D. Experimental Variable – 1. always and independent variable 2. the one thing you are testing

Steps to the scientific method

QUESTION: State the question to be answered. Example: Which type of tape will hold a poster on the wall the longest?

BACKGROUND RESEARCH: Research information related to the question. Find out if similar experiments have been done or similar methods have been used. Learn as much as you can about the topic of interest Scientists must complete this step in order to get funding for their research.

HYPOTHESIS: An educated guess based on your background research. A working hypothesis should have two parts.

HYPOTHESIS: REASONING STATEMENT A reasoning statement should state the prediction and be followed by a brief explanation of why that is the expected result. Students should state their prediction followed by “because” and tell why they think that will be the result. Example: “Grass seeds will not grow without sunlight because plants need light for photosynthesis.”

HYPOTHESIS: IF THEN STATEMENT An if/then statement should follow the following format: If my hypothesis is correct then this is the experimental result I will see. If then statements are written before the experiment is carried out in order to ensure that the experiment will, in fact, answer the question. It also ensure that you are aware of the variables that you are looking for! You should know what your results mean because you have done the research! :0)

HYPOTHESIS: IF THEN STATEMENTS CONT'D Another way to explain an if/then statement is If experimental variable then dependent variable. Example: If grass seeds need light to germinate then seeds placed in the dark will not germinate.

EXPERIMENT: Design a scientific experiment that includes both a control set-up and a an experimental set-up. The experimental set-up includes both experimental and dependent variables The experimental variable is the one thing that is being testing Independent Variable: any variable determined by the scientist. Can fill in data table ahead of time. Includes the experimental variable Dependent Variable: variable measured, the one that may depend on the experimental variable.

EXPERIMENT CONT'D: Experimental Set-Up: this is designed to measure the effect of changing the experimental variable (the thing that you will be testing). The experimental variable is always an independent variable. Control Set-Up: should be exactly the same as the experimental set-up except that the experimental variable is not changed. The control is used as a standard of comparison for the experimental group. The control group is often “normal conditions” All of the things are the same between the control set-up and experimental set-up are called controlled variables.

RESULTS: Make observations and take measurements during the experiment. Record them and analyze them using graphs. Data Tables: must include a title that begins with Table #. must include headings for each column and row Each heading must include a variable being recorded and the units used. Graphs: must include a title that begins with Figure # Independent variable must be on the x-axis Dependent variable must be on the y-axis Axes must be labeled with the variable name and units

CONCLUSION: Determine if the results of your experiment supported your hypothesis. Refer to specific data from the experiment as justification for supporting or rejecting your hypothesis. Comment on outside factors that may have affected your results.

PUBLISH: Students publish lab reports. Scientists publish research articles in scientific journals. In the world of science the saying “publish or perish” is a fact of life!

Order of Steps in Scientific Method State question Do background research Write hypothesis : reasoning statement Design experiment Write hypothesis : if ….then statement Conduct experiment Results : collect and analyze data Draw conclusions Publish Results