Chapter 1: Biology and You
SECTION 3: SCIENTIFIC PROCESSES
OBJECTIVES
Describe the stages common to scientific
investigations.
 Distinguish between forming a hypothesis and
a theory.

OBSERVATION: THE BASIS OF SCIENTIFIC
RESEARCH

Observation is the
act of noting or
perceiving objects
or events using
the senses.
OBSERVATION: THE BASIS OF SCIENTIFIC
RESEARCH
All scientists have a
certain way of
investigating the world.
 Scientific investigations
begin with observations.
 Observations cause
scientists to ask
questions about their
observations

STAGES OF SCIENTIFIC INVESTIGATIONS

Scientific investigations tend to have common
stages.
 These
stages are called the Scientific Method.
 There is more than one way to conduct an
investigation.
 Scientific Methods or Scientific Processes are more
accurate terms for the stages of scientific
investigation.
REAL LIFE EXAMPLES OF
SCIENTIFIC METHOD THAT
INVOLVES
STAGES OF SCIENTIFIC INVESTIGATIONS

Scientific Processes include the following steps:
1.
2.
3.
4.
5.
Collecting observations.
Asking questions
Forming hypothesis
Confirming predictions (with experiments when
needed)
Drawing conclusions
STAGES OF SCIENTIFIC INVESTIGATIONS

Hypothesis – an explanation that might be true,
a statement that can be tested by additional
observations or experimentation.
 Educated Guess

Prediction – the expected outcome of a test,
assuming the hypothesis is correct
STAGES OF SCIENTIFIC INVESTIGATIONS

Experiment – a
planned
procedure to test
a hypothesis.
WITHIN THE EXPERIMENT

Control group – a group in an experiment that
receives no experimental treatment. The
control group is necessary for comparing the
results of the experiment.
WITHIN THE EXPERIMENT

Independent variable - the factor that is
changed in an experiment.

Dependent variable – the variable that is
measured in an experiment, the outcome of the
dependent variable depends on what is done to
the independent variable.
DRAWING CONCLUSIONS

Once data is
collected and
analyzed, a
conclusion is made
as to whether the
data supports the
hypothesis.
VIEWING CONCLUSIONS IN CONTEXT
There is often more
than one possible
reason for a result.
 All the factors that
may affect an
outcome must be
considered.

SCIENTIFIC EXPLANATIONS

Constructing a Theory
 What is a theory?
 Theory – a set of related
hypotheses that have
been tested and
confirmed many times by
many scientists.
CONSTRUCTING A THEORY
A theory unites and explains a broad range of
observations.
 The word theory is used by the general public to
mean a guess, or lack of certainty.
 In science, a theory is a well-supported
scientific explanation that makes useful
predictions.

SCIENTISTS REPORT THEIR RESULTS
Scientific reports are
reviewed by other
scientists.
 Scientific reports allow
other scientists to use the
information obtained in an
experiment.
 Scientific reports also allow
other scientists to repeat
and test experiments.
