THE SCIENTIFIC METHOD

Transcription

1 THE SCIENTIFIC METHOD Created by: Mrs. Herman 2012

2 STEP 1: ASK QUESTIONS Develop a question or problem that can be solved through experimentation.

3 EXAMPLES AND NON-EXAMPLES Do students learn better before or after eating? How do students learn best? Do big flowers have better smells? Does singing to a plant increase the plant s size? *Tip* You must be able to measure the results in some way for it to be considered a testable question.

4 STEP 2: OBSERVE AND RESEARCH Make observations and research your topic.

5 Observations vs Inferences OBSERVATIONS Any information collected with the senses. Quantitative measureable or countable 3 meters long 4 marbles 50 kilograms 35 degrees Celsius Qualitative describable, not measureable red flowers smells like fresh baked cookies Tastes bitter

6 Observations vs Inferences INFERENCE Conclusions or deductions based on observations. The process of drawing a conclusion from given evidence. Practice: Observations: I hear people screaming I smell cotton candy, popcorn, and hamburgers I see a lot of people Inference =?

7 PRACTICE: OBSERVATION OR INFERENCE? The bell is ringing. observation

8 PRACTICE: OBSERVATION OR INFERENCE? The flower has red petals. observation

9 PRACTICE: OBSERVATION OR INFERENCE? There is a lot of red in the painting so the artist must have been angry. inference

10 PRACTICE: OBSERVATION OR INFERENCE? The dog has 3 legs. observation

11 PRACTICE: OBSERVATION OR INFERENCE? My mom is angry. inference

12 PRACTICE: OBSERVATION OR INFERENCE? The cat is on top of the table. observation

13 PRACTICE: OBSERVATION OR INFERENCE? The kids are smiling, they must be happy inference

14 PRACTICE: OBSERVATION OR INFERENCE? The man has a mustache. observation

15 PRACTICE: MAKE AN OBSERVATION

16 PRACTICE: MAKE AN INFERENCE

17 PRACTICE: MAKE AN OBSERVATION

18 PRACTICE: MAKE AN INFERENCE?

19 VARIABLES IN AN EXPERIMENT TEST VARIABLE (also called the independent variable) is a factor that is changed Example: In an experiment to see how different soils affect the growth (or height) of plants, the test variable would be the different kinds of soil.

20 VARIABLES IN AN EXPERIMENT OUTCOME VARIABLE (also called the dependent variable) is a factor that is the result of something being changed. It is observable or measurable. Example: In an experiment to see how different soils affect the growth (or height) of plants, the outcome variable is the height of the plants.

21 VARIABLES IN AN EXPERIMENT CONSTANT are factors that do not change during an experiment. Example: In an experiment to see how different soils affect the growth (or height) of plants, the constants would be the amount of sunlight, amount of water, type of plant, etc.

22 VARIABLES IN AN EXPERIMENT CONTROL a standard against which other conditions can be compared. Example: In an experiment to see if you add sugar to the soil to help plants grow taller, your control would be a plant without the sugar. All other variables would be the same.

23 PRACTICE Question 1: Will more birds visit the schoolyard if we put up a birdbath? Test Variable: Putting a birdbath in the school courtyard. Outcome Variable: The number of birds

24 PRACTICE Question 2: Does the height of the grass affect the number of robins feeding? Test Variable: Height of the grass. Outcome Variable: The number of robins.

25 STEP 3: FORMULATE A HYPOTHESIS Predict a possible answer to the problem or question. Must be written in an if/then/because statement

26 STEP 3: FORMULATE A HYPOTHESIS Also written as: If (test variable), then (outcome variable) because (fact from research). Example: If a plant is watered everyday, then it will grow faster because plants need water to grow.

27 STEP 4: EXPERIMENT DESIGN Some things to remember when developing an experiment: Designing an experiment involves developing a step by step procedure. Procedure is in a list Must include a detailed materials list. o o o The outcome of the experiment must be measureable (quantifiable).

28 EXPERIMENT VS. INVESTIGATION: WHAT IS AN EXPERIMENT? Following the scientific method and doing an experiment to find evidence to support or not support a hypothesis. Example: What kind of liquid helps a plant grow taller?

29 EXPERIMENT VS. INVESTIGATION: WHAT IS AN INVESTIGATION? using observations to study the natural world without inference or manipulation. Example: Walking around school to observe and record different types of organisms in order to create a food web.

30 STEP 5: COLLECT AND ANALYZE RESULTS Includes tables, graphs, pictures, etc.

31 HOW TO SET UP YOUR GRAPH!

32 HOW TO SET UP YOUR GRAPH! Y Axis This is for your outcome (dependent) variable

33 HOW TO SET UP YOUR GRAPH! X Axis This is for your test (independent) variable

34 TAILS Teachers s Favorite Singer T - Title

35 TAILS Teachers s Favorite Singer T - Title A - Axis Y Axis = Outcome Variable X Axis = Test Variable

36 TAILS Decide on an appropriate scale for each axis. Choose a scale that lets you make the graph as large as possible for your paper and data T - Title A Axis S Scale

37 HOW TO DETERMINE SCALE Favorite Singer Number of Teachers Toby Keith 22 Madonna 15 Elvis 11 Scale is determined by your highest & lowest number. In this case your scale would be from Sting 5 Sinatra 2

38 HOW TO DETERMINE INTERVALS Favorite Singer Number of Teachers Toby Keith 22 Madonna 15 Elvis 11 Sting 5 Sinatra 2 The interval is decided by your scale. In this case your scale would be from 2 22 and you want the scale to fit the graph. The best interval would be to go by 5 s.

39 TAILS The amount of space between one number and the next or one type of data and the next on the graph. The interval is just as important as the scale Choose an interval that lets you make the graph as large as possible for your paper and data T Title A Axis I Interval S Scale

40 TAILS Teachers s Favorite Singer T Title A Axis I Interval 0 S Scale

41 Number of Teachers TAILS Teachers s Favorite Singer T Title A Axis I Interval 0 LABEL your bars or data points Singers L Labels S Scale

42 Bar graphs WHEN TO USE Used to show data that are not continuous. Allows us to compare data like amounts or frequency or categories Allow us to make generalizations about the data Help us see differences in data Line Graphs For continuous data useful for showing trends over time

43 DATA COLLECTION: GRAPHS AND CHARTS 2005 Playoffs Number of Games Played Player Games Played Tim Duncan 23 Manu Ginobili 23 Tony Parker 23 Robert Horry 23 Nazr Mohammed 23 Brent Barry 23 Bruce Bowen 23 Glenn Robinson 13 Beno Udrih 21 Devin Brown 12 Rasho Nesterovic 15 Tony Massenburg 9

44 NUMBER OF GAMES PLAYED IN THE 2005 PLAYOFFS

45 DATA COLLECTION: GRAPHS AND CHARTS San Antonio Spurs Games Won Each year Year Games won

46 STEP 6: CONCLUSION A conclusion is a summary of information gained during experimentation. Should be a paragraph or more

47 STEP 6: FORMAT OF A CONCLUSION Restate Problem or question Restate your hypothesis (It was predicted that ) Accept or reject your hypothesis My hypothesis was supported by the data or My hypothesis was not supported by the data State the Facts (Provide evidence) Actual data from the experiment (What did the data say?) Relationships or trends in the data (Provide evidence) Discuss any questions you may still have or what you would do different next time. Issues or problems with the investigation (Provide evidence) Wrap it up! Concluding sentence with transition word, rephrased problem, and explain Why the experiment was important.

48 STEP 7: COMMUNICATE RESULTS Present the project results to an audience.

49 PRACTICE Bart Simpson believes that mice exposed to microwaves will become extra strong (maybe he s been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. (Do not do this at home. Bart is a misguided fictional character ) He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found that 8 out of the 10 microwaved mice were able to push the block away. 7 out of the 10 non-microwaved mice were able to do the same.

50 PRACTICE 1. Identify the problem / question 2. Observe / research 3. Hypothesis 4. Experiment 5. Collect and analyze data 6. Conclusion 7. Communicate results

51 PRACTICE: OBSERVATION OR INFERENCE? They boy has tears in his eyes, so he must be sad. inference

52 REPLICATION VS. REPETITION Repetition is when the same scientist completes multiple trials to limit the bias of experiment.

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54 REPLICATION VS. REPETITION Replication is when a different scientist completes the experiment by following the same procedures. Replication is done to get same/similar results which validate the experiment.

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56 PRACTICE Can you explain the difference between repetition and replication and identify their role in a controlled experiment? Which picture below represents replication and which represents repetition? Repetition same scientist Replication different scientist

57 Why would a scientist use repetition in an experiment? To verify the accuracy and results of the experiment. To find possible flaws in their experiment Why would a scientist replicate an experiment? So scientists can check to see if a controlled experiment was conducted and that good scientific practices were used. This is called peer review

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