Download The scientific method begins with observations that lead to the

scientificmethod.notebook
August 22, 2013
The scientific method begins with observations that lead to the asking of questions.
Observations include using your senses to study the world, but can also include computers and other technology to collect data.
Observations result in data, there are two types:
­Qualitative is a description of a phenomenon occurring.
­Quantitative are characteristics that can be counted or measured.
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scientificmethod.notebook
August 22, 2013
Research
­What has already been studied on this topic?
­What experiments or studies have been done and what are the results?
­What do you need to know before you can begin your experiment?
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scientificmethod.notebook
August 22, 2013
Scientist then use the observations and research to form a hypothesis.
A hypothesis is a proposed answer for a scientific question.
A hypothesis is written as a statement, must be testable and include the independent and dependent variable.
When biologist test hypotheses they must test them multiple times, why?
­By repeating tests, scientists can be certain their results are not mistakes or one time occurrences.
If the data does not support a hypothesis, it is rejected. However, this data can lead to new hypotheses. 3
scientificmethod.notebook
August 22, 2013
In order to test hypotheses, an experiment must be set up.
In an experiment there must be independent and dependent variables.
Independent variables­ the condition or factor that is changed or manipulated by a scientist.
Dependent variables­ the condition that is observed or measured during an experiment.
A change in a dependent variable will only occur if the independent variable changes.
Only 1 independent variable should be manipulated at a time. All other conditions must stay the same.
Constants/Controls­ conditions that do not change during an experiment.
In an experiment scientists will have a control group and an experimental group. The control group receives the same treatment as the experimental group with the exception of the independent variable.
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scientificmethod.notebook
August 22, 2013
Many times when a drug or treatment is being tested a placebo will be used.
A placebo is a substance that has no treatment value, but has the same outward appearance of the drug.
A double blind procedure is also usually done meaning the doctor and the patient do not know who is receiving the treatment.
This helps to reduce bias.
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scientificmethod.notebook
August 22, 2013
Design an Experiment
Needs to have specific, detailed, step by step procedures. Must be testing your hypothesis.
Record and Organize data
Develop data table that fits experiment.
Leave room to record qualitative observations.
Then develop a paragraph that summarizes all the data into words.
Draw conclusions
What is the final result?
Was your hypothesis correct? Why or why not?
What possible errors might have occurred?
What is your next question?
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scientificmethod.notebook
August 22, 2013
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scientificmethod.notebook
August 22, 2013
The word "theory" in everyday life usually means a guess or a speculation, this is NOT the scientific meaning.
A theory is a proposed explanation of a wide range of observations and experimental results that is supported by a wide range of evidence.
Natural Selection is a scientific theory, that has a large amount of data to support it. Theories are not easily excepted in science and are never proven. They are always subject to change.
Theories can change based on new evidence.
Example: Up until the mids 1800's it was believed illnesses were caused by supernatural powers or imbalances in the bodies fluids.
Then scientific research suggest that illnesses were caused by microscopic organisms, such as bacteria. This was developed into the germ theory.
Even this theory was altered in the 1980's when prions were discovered to cause Creutzfeldt­Jakob disease. Prions are non­living misfolded proteins.
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