Biologist ______________________________
Date _______________
Chapter 1-1: What is Science? Outline
KEY QUESTIONS: What are the goals of science? What procedures are at the core of
scientific methodogy?
I. What Science is and is not
A. Science as a way of knowing
Science is an organized way of gathering and analyzing evidence about the natural word.
- Science is different from other human works (endeavors) in the following ways:
o Science deals only with the natural world
o Scientists collect and organize information about the natural world in an
orderly way.
o Scientists propose explanations that are based on evidence, not belief.
o They test those explanations with more evidence.
B. The Goals of Science
- The goals of science are to provide natural explanations for events in the natural world
and to use those explanations to make useful predictions.
C. Science, Change, and Uncertainty
- Scientific discoveries change allowing science to advance and solve new mysteries of the
universe
- Scientists aim to understand the natural world, not to “prove” facts
II. Scientific Methodology: The Heart of Science
- Figure 1-3 shows a salt marsh example in which scientists made an observation about
grasses of different heights. They inferred that grass in some areas must be limited in
growth and created a hypothesis that they were limited in nitrogen. They designed a
controlled experiment with a control and experimental group. After collecting and
analyzing their data they were able to conclude that marsh grasses with additional
nitrogen were able to grow taller than the other control groups.
A. Observing and Asking Questions
- First scientists make an observation, which involves the act of noticing and describing
B.
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events or processes in a careful, orderly way.
Inferring and Forming a Hypothesis
Scientists then use their observations to make inferences.
An inference is a logical interpretation based on what scientists already know.
Next, scientists suggest hypotheses.
A hypothesis is a scientific explanation for a set of observations that can be tested
in ways that support or reject it.
C. Designing Controlled Experiments
- Next, scientists test the hypothesis.
- Testing a hypothesis often involves designing an experiment. Whenever possible, a
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hypothesis should be tested by a controlled experiment an experiment in which only
one variable (the independent variable, or manipulated variable) is changed.
Example of a variable: amount of light, temperature, etc.
a. Controlling Variables
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Only one variable can be altered, or changed to allow the researcher to easily tell
what is responsible for the observed changes.
The variable that can change in response to the independent variable is called the
dependent variable, or responding variable.
b. Control and Experimental Groups
An experiment has both groups normally.
The control group is exposed to the same conditions as the experimental group
except for one independent variable.
In order to replicate data, researchers use several control and experimental groups.
D. Collecting and Analyzing Data
- Scientist then collect record and analyze data – or information gathered during the
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experiment.
Data is either quantitative – numbers (25 sec) or qualitative – descriptive (short)
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Examples: calculators, meter stick, graphs, journals, computers, etc.
E.
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To limit error data analysis and sample sizes must be carefully considered.
Usually the larger the sample size the more reliable the results.
a. Research Tools
b. Sources of Error
Drawing Conclusions
Based on data to either support, refute, or revise the hypothesis being tested to
come to a valid conclusion.
F. When Experiments are Not Possible
- Example: animal behavior, human subject studies, medical research