1. Virginia Standard of Learning BIO.1a-m
The Scientific Method
Virginia Standard of Learning BIO.1a-m

2. BIO SOL: 1 a-m
The student will plan and conduct investigations in which:
observations of living organisms are recorded in the lab and in the field;
hypotheses are formulated based on direct observations and information from scientific literature;
variables are defined and investigations are designed to test hypotheses;
graphing and arithmetic calculations are used as tools in data analysis;
conclusions are formed based on recorded quantitative and qualitative data;
sources of error inherent in experimental design are identified and discussed;

3. BIO SOL: 1 a-m
The student will plan and conduct investigations in which:
validity of data is determined;
chemicals and equipment are used in a safe manner;
appropriate technology including computers, graphing calculators, and probeware, is used for gathering and analyzing data and communicating results;
research utilizes scientific literature;
differentiation is made between a scientific hypothesis and theory;
alternative scientific explanations and models are recognized and analyzed; and
a scientific viewpoint is constructed and defended (the nature of science).

4. The Scientific Method
An organized way to solve a problem through experimentation & observation.

5. The 6 Steps of the Scientific Method

6. 1. State the Problem
Form a question about a specific event or reaction
EX: Mouthwash kills bacteria. Which brand works best?

7. 2. Collect Information Research the problem
EX: Read the labels of 3 common brands of mouthwash and see which has the most antiseptic (germ-killing) ingredients.

8. 3. Form a hypothesis Make an educated guess based on your research.
A hypothesis can be recognized by an “if, then” statement.
EX: If Listerine has more antiseptic ingredients than Scope or Wal-Mart brand, then it will kill more bacteria.

9. 4. Design an Experiment Devise a way to test your hypothesis. Create a
CONTROLLED
experiment.

10. ONLY 1 condition is changed!
A controlled experiment MUST have 2 groups.
CONTROL GROUP: all conditions remain the same
EXPERIMENTAL GROUP: only the condition that you are testing for is changed
ONLY 1 condition is changed!

11. Establish the variables for your experiment.
INDEPENDENT VARIABLE: the variable that is changed, manipulated (X axis for graphing)
DEPENDENT VARIABLE: the change caused by the manipulation of the independent variable (Y axis for graphing)

12. Mouthwash Experiment Control Group -no mouthwash Experimental Group
Petri dish
Bacteria grown from swab
Listerine
Experimental Group
Scope
Wal-Mart brand

13. Mouthwash Experiment INDEPENDENT VARIABLE: Type of Mouthwash
Amount of bacteria killed

14. 5. Collect & Analyze Data
Run the experiment & document the data

15. 2 Types of Data
QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart
QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

16. QUANITATIVE EX: Area of Inhibition for Mouthwash Brands
QUALITATIVE EX: The control group and the Wal-Mart brand have a strong smell; the Listerine & Scope don’t smell as bad.
QUANITATIVE EX: Area of Inhibition for Mouthwash Brands
Control
Listerine
Scope
Wal-Mart
5 min
0 mm
3 mm
2 mm
1 mm
10 min
4 mm
15 min
6 mm
5 mm
20 min
8 mm

17. 6. Draw Conclusions
Determine from the data collected if the hypothesis was correct or incorrect
EX: Listerine did kill more bacteria than the other brands because it had more antiseptic ingredients.

18. Progression of Ideas in Science
Hypothesis- a possible explanation to a question based on information the scientist has already gathered
- If experiments show a hypothesis to be correct, other scientists may accept it as support for a scientific theory.
EX: Plants obtain their energy from the sun.

19. Progression of Ideas in Science
Scientific Theory- a general statement of why things work based on hypotheses that have been tested many times

20. Progression of Ideas in Science
- Theories are used to explain & predict the outcome of other experiments
- Theories must be tested
- Sometimes they are wrong & must be modified or discarded
EX: The Earth is flat.

21. Progression of Ideas in Science
Scientific Law- a statement of what happens in a certain event based on verified observations & experiments

22. Progression of Ideas in Science
- Explains what happens & not why
- Summaries of the results of many, many experiments & observations
- When results of a series of experiments are the same each time they no longer need to be tested
EX: Newton’s Law of Gravity

23. Progression of Ideas in Science
Which one is most likely to be wrong- hypothesis, theory, or law? 1. 2. 3.
Hypothesis
Theory
Law

24. Scientific Method Vocabulary
Observation- the act of observing (touch, taste, smell, feel, see, etc.)
Inference- a quick conclusion that attempts to explain an observation
Prediction- to forecast; to guess the outcome of a situation beforehand
Analysis- to separate or break apart into smaller sections for study

25. Scientific Method Vocabulary
Conclusion- to close or bring to an end; to accept or reject a hypothesis in an experiment
Data- recorded observations or measurements
Hypothesis- a tentative explanation that accounts for a set of facts & that can be tested by further investigation

26. Scientific Method Vocabulary
Theory- an explanation of a large body of information, experimental and inferential, and serves as an overarching framework for numerous concepts. It is subject to change as new evidence becomes available.
Law- a basic scientific theory that is no longer tested & is generally accepted as true (Newton’s Law of Gravity)

27. Scientific Method Vocabulary
Controlled Experiment- an experiment in which all variables except the ONE being tested are identical in order to make the experiment fair & the results reliable
Variable- any factor in an experiment that could affect the results & is therefore tested separately

28. Scientific Method Vocabulary
Controlled Variable- a variable that is not changed
Independent Variable – a variable that you purposely manipulate (manipulated variable)
Dependent Variable- the variable being observed that changes in response to the independent variable (responding variable)

29. Scientific Method Vocabulary
Quantitative Data- data that involves numbers or measurement usually in the form of a chart or graph
Qualitative Data- anecdotal or descriptive data that does NOT involve numbers or measurement