1. The Nature of Science - Unit 1 Scientific Method

2. The Scientific Method involves a series of steps that are used to investigate a natural occurrence.

3. Observation/Research Formulate a Hypothesis Experiment
Scientific Method
Problem/Question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion
Communicate the Results

4. Steps of the Scientific Method
1. Problem/Question: Develop a question or problem that can be solved through experimentation.

5. Begin by asking a question about your topic
DEFINE THE PROBLEM
Begin by asking a question about your topic
What is a good question for an experiment?
One that is testable with the materials at hand

6. Steps of the Scientific Method
2. Observation/Research: Make observations and research your topic of interest.

7. Now we need a hypothesis to guide our investigation.
What is a hypothesis?
An explanation based on evidence
Your best thinking about how the change you make might affect another factor Tentative or trial solution to the question. An if ………… then ………… statement.

8. Steps of the Scientific Method
3. Formulate a Hypothesis: Hypothesis an explanation to of the possible answer to the problem or question.
Example: If soil temperatures rise, then plant growth will increase.

9. Variables Variables are things that change.
The independent variable is the variable that is purposely changed. It is the manipulated variable.
The dependent variable changes in response to the independent variable. It is the responding variable.
Be sure to operationally define each variable.

10. Factors that are kept the same and not allowed to change
Constants in an Experiment
What are constants in an experiment?
Factors that are kept the same and not allowed to change

11. The part of the experiment that serves as the standard of comparison.
The Control in an Experiment
What is a control?
The part of the experiment that serves as the standard of comparison.
Why is a control necessary?
It is the unchanged part of the experiment that detects the effects of hidden variables.

12. Steps of the Scientific Method
4. Experiment: Develop and follow a procedure.
Include a detailed materials list.
The outcome must be measurable (quantifiable).

13. Qualitative Observations and Results
What are qualitative observations?
They are what you perceive that occurred during the course of your experiment. They are identification of trends in the data.

14. Quantitative Observations and Results
What are quantitative observations?
Numbers in the form of raw data displayed in data tables and graphs

15. Steps of the Scientific Method
5. Collect and Analyze Results: Modify the procedure if needed.
Confirm the results by retesting.
Include tables, graphs, and photographs.

16. Steps of the Scientific Method
6. Conclusion: Include a statement that accepts or rejects the hypothesis.
Make recommendations for further study and possible improvements to the procedure.

17. Steps of the Scientific Method
7. Communicate the Results: Be prepared to present the project to an audience.
Expect questions from the audience.

18. Let’s put our knowledge of the Scientific Method to a realistic example that includes some of the terms you’ll be needing to use and understand.

19. She explains that yeast releases a gas as it feeds on sugar.
Problem/Question
John watches his grandmother bake bread. He ask his grandmother what makes the bread rise.
She explains that yeast releases a gas as it feeds on sugar.

20. Problem/Question
John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

21. Caution! Be careful how you use effect and affect.
Effect is usually a noun and affect, a verb.
“ The effect of sugar amounts on the rising of bread.”
“How does sugar affect the rising of bread?”

22. Observation/Research
John researches the areas of baking and fermentation and tries to come up with a way to test his question.
He keeps all of his information on this topic in a journal.

23. John talks with his teacher and she gives him a Experimental Design Diagram to help him set up his investigation.

25. Formulate a Hypothesis
After talking with his teacher and conducting further research, he comes up with a hypothesis.
“If more sugar is added, then the bread will rise higher.”

26. Note: These variables will be defined in the next few slides.
Hypothesis
The hypothesis is an educated guess about the relationship between the independent and dependent variables.
Note: These variables will be defined in the next few slides.

27. Independent Variable
The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter.
John is going to use 25g., 50g., 100g., 250g., 500g. of sugar in his experiment.

28. In this case, it would be the size of the loaf of bread.
Dependent Variable
The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable.
In this case, it would be the size of the loaf of bread.

29. She discusses with John how to determine the control group.
Experiment
His teacher helps him come up with a procedure and list of needed materials.
She discusses with John how to determine the control group.

30. Control Group
In a scientific experiment, the control is the group that serves as the standard of comparison.
The control group may be a “no treatment" or an “experimenter selected” group.

31. All experiments should have a control group.
The control group is exposed to the same conditions as the experimental group, except for the variable being tested.
All experiments should have a control group.

32. Control Group
Because his grandmother always used 50g. of sugar in her recipe, John is going to use that amount in his control group.

33. Constants
John’s teacher reminds him to keep all other factors the same so that any observed changes in the bread can be attributed to the variation in the amount of sugar.

34. Constants
The constants in an experiment are all the factors that the experimenter attempts to keep the same.

35. Can you think of some constants for this experiment?

36. Constants They might include:
Other ingredients to the bread recipe, oven used, rise time, brand of ingredients, cooking time, type of pan used, air temperature and humidity where the bread was rising, oven temperature, age of the yeast…

37. Experiment
John writes out his procedure for his experiment along with a materials list in his journal. He has both of these checked by his teacher where she checks for any safety concerns.

38. John is going to test each sugar variable 3 times.
Trials
Trials refer to replicate groups that are exposed to the same conditions in an experiment.
John is going to test each sugar variable 3 times.

39. Collect and Analyze Results
John comes up with a table he can use to record his data.
John gets all his materials together and carries out his experiment.

40. Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of Sugar (g.) 1 2 3
Average
Size (cm3) 25
768
744
761
758 50
1296
1188
1260
100
1080
1116
250
672
576
588
612
500
432
504
360
Control group

41. Collect and Analyze Results
John examines his data and notices that his control worked the best in this experiment, but not significantly better than 100g. of sugar.

42. Conclusion
John rejects his hypothesis, but decides to re-test using sugar amounts between 50g. and 100g.

43. Once again, John gathers his materials and carries out his experiment.
Here are the results.

44. Can you tell which group did the best?

45. Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of Sugar (g.) 1 2 3
Average
Size (cm3) 50
1296
1440
1344 60
1404
1380 70
1638
1560
1612 80
1332 90
1080
1200
972
1084
Control group

46. Conclusion John finds that 70g. of sugar produces the largest loaf.
His hypothesis is accepted.

47. Communicate the Results
John tells his grandmother about his findings and prepares to present his project in Science class.

48. Observe your world and come up with a question to answer using the Scientific Method!

49. What is the purpose of a graph?
Constructing a Graph
What is the purpose of a graph?
Graphs communicate in pictorial form the data collected in an experiment

50. Independent Variable – include units and an appropriate scale
Graphs
Title: The Effect of the independent variable on the dependent variable
Dependent Variable – include units and an appropriate scale
Independent Variable – include units and an appropriate scale

51. The type of graph to use depends on the type of data collected.
Bar vs. Line Graphs - Which Should I Use?
The type of graph to use depends on the type of data collected.
Two kinds of data: Discrete and Continuous
Discrete data are categorical like days of the week, color, and brand of battery. Intervals between the data have no meaning.
USE A BAR GRAPH
Continuous data are associated with measurements
involving a standard scale. Measurements should be able to show a trend or relationship. Intervals between data have meaning.
USE A LINE GRAPH

52. Constructing a Graph DRAW AND LABEL AXES
Y Axis - Dependent Variable
Temp. of Water (oC)
Amount of Calcium Chloride (scoops)
X Axis - Independent Variable

53. Constructing a Line Graph - DETERMINE SCALES FOR AXES
Increase values on axes by 1, 2 ,5, 10 or
multiples of 10. There should be about
5 numbered subdivisions on each axis. 20 15
X: Largest value – Smallest value = Range
10 scoops - 0 scoops = 10 scoops
10 scoops divided by 5 = 2 scoops 10
Average Temp. change (o C)
Y: Largest value – Smallest value = Range oC – 0 oC = 17 oC o C divided by 5 = 3.4 or ~ 5 oC 5
Amount of calcium chloride (scoops)

54. . . . . . . Constructing a Line Graph – PLOT DATA PAIRS 20
(0, 0)
(2, 4)
(4, 7)
(6, 10)
(8, 14)
(10, 17) . 15 .
Average Temp. change (deg C) 10 . . 5 .
Amount of calcium chloride (scoops)

55. . . . . . . Constructing a Line Graph – TITLE THE GRAPH 20 15
THE EFFECT OF ADDING VARIOUS AMOUNTS OF CALCIUM CHLORIDE ON THE TEMPERATURE OF WATER . 20 . 15 .
The title should state the effect of the independent variable on the dependent variable. 10 .
Average Temp. change (oC) . 5 .
Amount of calcium chloride (scoops)

56. Benchmarks Vocabulary: Theory Law Objective(s):
Distinguish between scientific theories and laws.
Identify examples of scientific theories
Identify example of scientific laws.
SC.7.N.3.1-Recognize and explain the difference between theories and laws and give several examples of scientific theories and the evidence that supports them. (Also assesses SC.6.N.3.1 and SC.8.N.3.2.)

57. Theories vs. Laws
Theories: An explanation for why natural events occur developed from extensive observations, experimentation, and reasoning.
LAWS: A scientific principle that states what occurs during a natural event developed from extensive observations and experimentation.

58. BILLY PASSED A TEST. SORT THESE as a Law or Theory! RIGHT SIDE
I passed because I studied for two hours and got a good night's sleep.
I got a 94% score, and missed the questions about gravity. 58

59. LAW: I got a 94% score, and missed the questions about gravity. - WHAT
Why!
BILLY PASSED A TEST
THEORY: I passed because I studied for two hours and got a good night's sleep. -WHY
LAW: I got a 94% score, and missed the questions about gravity. - WHAT

60. Theories vs. Laws Theories: WHY things are this way. Plate tectonics
Cell theory
Evolution
LAWS: What we observe.
Law of Superposition.
Conservation of matter
Natural selection