Presentation on theme: "The Scientific Method Virginia Standard of Learning BIO.1a-m."— Presentation transcript:
The Scientific Method Virginia Standard of Learning BIO.1a-m
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;
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).
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? HypothesisTheoryLaw 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)
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
The Scientific Method An organized way to solve a problem through experimentation & observation.
1. State the Problem Form a question about a specific event or reaction EX: Mouthwash kills bacteria. Which brand works best?
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.
3. Form a hypothesis Make an educated guess based on your research. EX: If Listerine has more antiseptic ingredients than Scope or Wal-Mart brand, then it will kill more bacteria. A hypothesis can be recognized by an “if, then” statement.
4. Design an Experiment Devise a way to test your hypothesis. Create aCONTROLLEDexperiment.
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)
Mouthwash Experiment Petri dish Bacteria grown from swab Control Group -no mouthwash Experimental Group Listerine Scope Wal-Mart brand
Mouthwash Experiment INDEPENDENT VARIABLE: DEPENDENT VARIABLE: Type of Mouthwash Amount of bacteria killed
5. Collect & Analyze Data Run the experiment & document the data
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
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 ControlListerineScopeWal-Mart 5 min0 mm3 mm2 mm1 mm 10 min0 mm4 mm3 mm 15 min0 mm6 mm5 mm4 mm 20 min0 mm8 mm6 mm4 mm
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.