The Process of Science
Science is the quest to understand
nature.
Discovery Science
Emphasizes inquiry and observation
• Biology blends two main forms of
scientific exploration:
• Discovery Science – describes nature
• Hypothesis Science – explaining nature
• Most scientist practice a combination of
these two approaches.
Science as an
Inquiry
• Science is way of knowing
• It’s a way to answer questions about the natural
world.
• Curiosity is the starting point for exploring life
through inquiry.
• Inquiry is a process of investigation
• Asking questions is a natural activity for all curious
minds.
Penicillin
Alexander Fleminds (1928) Scottish Physician
• Was studying bacteria
• Found mold in some of his cultures
Penicillin
• Flemings was going to discard the samples
when he noticed bacteria was not growing
near the mold.
• That led to the discovery of penicillin
• This discovery lead to what we know about
antibiotics today.
Observations & Data
The questions that drive scientific inquiry are based on
observation.
Observation – the use of senses; such as
vision/hearing; to gather and record
information about structures or
process.
Data - recorded observation; items of information
• All observations depend on human senses.
• Scientific instruments vastly increase the range of possible
observation
Scientific Instruments
Astronomy – telescopes reveal other solar
systems, galaxies, etc.
Biology – microscopes
make it possible to observe life that
is invisible to the unaided eye.
Quantitative Data – Recordable observations
Is the modern form of the metric system and is generally a
system of units of measurements devised around seven base
units and the convenience of the number ten. It is the world's
most widely used system of measurements, both in everyday
commerce and in science.
Qualitative Data – data recorded as description instead
of measurements
Data can best support science when they are
clearly organized, consistently recorded,
and reliable.
Inferences In Science
Inferences – a logical conclusion based on
observation
• Can be from prior experience
• Inference is important in science because
they help refine general questions into
specific questions
Not an observation; but based on previous
observations
Inferences In Science
• Doorbell Ringing – An Observation
• Someone at the Door? – Inference
• Unless you can see through the door
• Could be a short circuit.
Generalization
A general conclusion
The example of the cell:
• Original discovery was in the 1600’s
• After many years of research it became
accepted that the cell makes up all living
things.
Hypothesis Based Science
A Search for Explanation
The grown up
concept!
Forming and Testing a Hypothesis
Hypothesis – a suggested answer to a welldefined scientific question.
• An explanation on trial
• Are usually concerned with natural
phenomena
• Often based on past experience of
knowledge gained from discovery science
or other sources
An Educated Guess
• People normally use hypothesis to solve
everyday problems.
• After you propose a hypothesis – you test
these ideas by making additional
observations or designing an experiment.
Hypothesis – If…. Then…..
• Additional observations allows you to make
predictions
• These predictions are tested.
A Hypothesis is written as an If… Then…
Statement.
If a particular hypothesis is correct, and you test that
hypothesis with a suitable experiment, then you
should expect a certain result for the experiment.
Hypothesis
• An incorrect hypothesis does not mean
failure
• Just wrong
• The inquiry continues with test of alternative
hypothesis.
Even when an experiment supports a
hypothesis curiosity can send you in a
new direction.
Science Generates Questions
A Case Study of Hypothesis – Based
Science
A Case Study – an in-depth examination of
something that actually happened
From: Observation → Question → Hypothesis
• Testing a Prediction of the Hypothesis
Designing a Controlled Experiment
Variable – A condition that can differ within
the experiment
Controlled Experiment – An experiment that
test the effect of a single variable
• In a controlled experiment scientist try to
eliminate (or control) other variables that could
affect the outcome
Variables
• Variables could include temperature,
humidity (if outside), light, and other
weather conditions
• Even in a lab total regulation of all but one
variable is not practical.
Eliminating Unwanted Variables
A Control Group
• Equals Cancelled out
Experimental Group
If…. Then….. Reasoning
Organizing Data and Interpreting Results
Often the results of an experiment only begin
to make sense after much analyze of the
data
Evidence in Science
Evidence – consists of a collected body of data,
form observations and experiments.
• Evidence is the information upon which
inferences are made.
Evidence in Science
• Evidence does NOT begin to convince
scientist until observations and experiments
have been repeated multiple times with
similar times.
• Attempts to repeat independently the
observations and experiments of others, is
common in science
Repeatability is the hallmark of scientific
evidence.
What makes a Hypothesis
Scientific?
In science, the only hypothesis that count are
those that meet the standards of testability.
Falsifiable – there must be some observation
or experiment that could reveal is such a
hypothesis is false.
• Scientist test a hypothesis many times and
in different ways.
What makes a Hypothesis
Scientific?
Even if a hypothesis that stand-up to repeated
testing may later be revised or even
rejected.
• A change can occur when new tools make
new kinds of observations and experiments
are possible.
Virus
Limitations of Science
Science requires repeatable observations and
testable answers to hypothesis.
• These standards restrict science to a search
for natural phenomena.
Limitations of Science
• Science can not or have an answer to the
unobservable or supernatural forces.
Science-based knowledge = confirmed observations/testable
hypothesis
Theories in Science
• Scientist are interested in finding patterns in
data
• Then expand on these patterns
• Now advances in science has allowed new
theories to tie together previously unrelated
facts.
Theory
A well tested explanation that makes sense of
a great variety of scientific observations
• Compared to hypothesis, a theory is much
broader in scope.
Models
Are physical, mental, or mathematical
representations of how people understand a
process or an idea.
Analogy
A comparison that shows a likeness between
two things
The brain is like a computer.
Communication in Science
Many scientist work in teams and are good
communicators
They share information:
Cooperation and competition characterize the
scientific culture.
Science, Technology, and Society
• Science and technology are related.
• Goals and methods are different
Technology – to apply scientific
understanding for specific purposes.
Biologist speak of Discoveries
Technologist (engineers) Speak of Inventions