Chapter 2 – Scientific Methods
What is the Scientific
Method?
Several Steps
Collecting data
Developing hypotheses
Testing hypotheses
Elevation of tested
hypotheses to theories
What is a Fact?
A phenomenon that has an
actual, factual existence
Must be observed
Through various senses
Not necessary to be direct
observations
Various instruments extend human senses
Data
Recording of observations
Qualitative
Oral or written descriptions with illustrations
Quantitative
Use of measurements and the recording of numbers
associated with them
Manipulation with statistics and equations
Examples of facts
Gravity
Numerous observations of falling objects
Biologic evolution
Development of new species over time
Quantum physics
Nuclear explosions
Former existence of dinosaurs
Body and trace fossils
Facts require
interpretation
What is a Hypothesis and How
is it Tested?
A CONDITIONAL explanaton
of an observed fact or series of facts
Typically proposes a cause
Characteristics
Testable
Falsifiable
Based on independently verifiable
and observable facts
Can be used to make
predicitions
an idea with no factual evidence supporting it
is not testable and is not scientific
Possibilities of testing a
hypothesis
Complete rejection
Complete acceptance
Modification of the hypothesis,
accepting part of it and rejecting part of it
Multiple hypotheses may be
used
Scientific procedures for
testing hypotheses
Tested by original
investigator/s usually
Summary of results undergo
PEER REVIEW
Other scientists familiar with the subject
matter who can critically evaluate the summary
Published in topic-specific
journal or science books if accepted by peer review
Publication in a journal shows conditional
acceptance of the hypothesis
It can still be rejected or modified based on
further testing by the scientific community
Textbooks are peer reviewed, but are secondary sources because none or
only a small part of the information presented is original research done by the
author
Proprietary information
Generally obtained by scientific methods by
scientists employed by private companies that is not “peer
reviewed” and rarely shared with the wider scientific community for
evaluation
World Wide Web publication
Vast majority of web page publications have NOT
undergone peer review and hypotheses published on the web should be viewed
skeptically
Publishing in the popular
press
Results promoted as “fact” before
examination by peer review
Examples
1998 news report of dinosaur tracks in Bolivia indicating that a 350 m long dinosaur made them
1999 National Geographic report of a feathered theropod with features shared
by both theropods and birds, Archaeoraptor liaoningensis
Predicting future observations on the basis of a hypothesis is one of the most effective and powerful ways to test it
Discovery of Archaeopteryx two years after publication of Darwin’s On
the Origin of Species by Means of Natural Selection, in which he predicted such transitional forms
between major taxa
Essence of hypothesis
building
Good description
Good interpretation
What is a Theory?
A hypothesis or set of
related hypotheses that has/have withstood repeated testing to the point of
widespread acceptance by the scientific community
Still subject to
falsification, but most likely merely refined and better understood over time
Best known theories
Gravitation
Biologic evolution
Quantum physics
Plate tectonics
Hypotheses or ideaw with
little or no factual evidence often MISTAKENLY called “theories”
Theories often have
universal applicability
Saying that an integrated
concept in science is “JUST A THEORY’ shows considerable ignorance
or deliberate misrepresentation of what constitutes a theory in science
What is an Opinion?
An idea based on feelings,
with or without a basis in fact, that are not scientific
Argument from authority
Using the views of an
authority in a scientific discipline to support what may be a mere opinion
Opinion polls carry no
weight in science
What is meant by
“proof”?
Scientific methods
don’t deal in “proof”
Scientific methods DISPROVE
hypotheses or theories
Observational Methods
Making Observations in the
Field
Walk around and look at
the ground
Must know where to look
Field partners important
Describe fossils in field
qualitatively and quantitatively
Statistics
Average/Mean and Range
Mean = Sum of All Values/Number
of Values
Range is the minimum and the maximum
Standard Deviation
Spread of data around a mean
Involves comparing each value with the mean
Each value is subtracted from the mean and squared
Squared differences for all values are summed
Sum is divided by the number of values less one
Standard deviation is the square root of the quotient
Ethics and Dinosaur
Studies
Monetary considerations and
Relationships with coworkers
Dinosaur fossils are worth
lots of money
Examples
The Tyrannosaurus rex specimen known as “Sue” sold for
$8.36 millon
Should paleontologists have to pay for access
to study specimens found on private land?
Unique or excellent specimens are not
uncommonly stolen before they can be properly studied or excavated
Not enough paleontologists to
study all specimens
Private collectors can preserve material that
would be eroded or damaged by weathering
Dinosaur paleontologists
don’t work alone
How should contributions by
amateurs be acknowledged?
How should graduate students
react to unethical use of their work by major professors?