the scientific method virginia standard of learning bio.1a-m
TRANSCRIPT
BIO SOL: 1 a-mThe 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;
BIO SOL: 1 a-mThe 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).
The Scientific Method• Scientific Knowledge is Testable
• Scientific Knowledge is reversible
• Scientific Knowledge is explanatory
• Scientific Knowledge is
interpreted from empirical evidence
Scientific Knowledge
Scientific Knowledge is Generative It breeds new questions
It has no real end point
3. Form a hypothesis• Make an educated prediction based
on your research. You need to have a reason for your prediction.
A hypothesis can be recognized by an “if, then” statement with “because”
Null Hypothesis
• A null hypothesis states there is no relationship between the measured conditions
You may accept or reject the null hypothesis
• 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!
• 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)
• 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
6. Draw Conclusions
• Determine from the data collected if the hypothesis was supported or was not supported
• Can you accept the null and reject your hypothesis
• Can you reject the null and reject your hypothesis
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.
Progression of Ideas in Science
• Scientific Theory- a general statement of why things work based on hypotheses that have been tested many times
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.
Progression of Ideas in Science
• Scientific Law- a statement of what happens in a certain event based on verified observations & experiments
Progression of Ideas in Science
- Explains what happens & not why
EX: Newton’s Law of Gravity
- 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
Progression of Ideas in Science
• Which one is most likely to be wrong- hypothesis, theory, or law?
Hypothesis Theory Law
1. 2. 3.
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
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
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)
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
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)