Virginia Standard of Learning 6.1 The Scientific Method Virginia Standard of Learning 6.1

SOL 6.1 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;

SOL 6.1 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).

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

6 Steps of the Scientific Method State the problem. Collect information Form a hypothesis Design experiment Collect & analyze data Draw Conclusions & communicate results

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. 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.

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

ONLY 1 condition is changed! A controlled experiment MUST have 2 groups. CONTROL GROUP: all conditions remain the same (to compare) 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: variable that I, the experimentor, change manipulated (X axis for graphing) DEPENDENT VARIABLE: it responds to the manipulation of the independent variable; it is measured. (Y axis for graphing)

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

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

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

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

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.

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

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 Scientific Law- a statement of what happens in a certain event based on verified observations & experiments

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 - 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

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

Scientific Method Vocabulary Observation- observing with the senses (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- educated guess that can be tested by further investigation

Scientific Method Vocabulary Theory- 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 (for comparison) Independent Variable –variable that I, the experimentor purposely change (manipulated variable) Dependent Variable- variable that is measured & responds 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- descriptive data involving words (does NOT involve numbers or measurement)