Scientific Method
Statistics and Quantitative
Analysis
The world was covered by a flood.
The story of the great flood is found in the Bible
.
The world was covered by a flood.
Stories of a great flood is common in many cultures as seen not only in the Bible,
but also in Mesopotamian flood stories,
as well as in Greek stories,
and in the lore of the K'iche' and Maya in Central America,
and the Ojibwa tribe and Pacific peoples of North America,
and the Muisca and Cañari people in South America.
And once there was a great flood!
But how old are the shell fossils on the top of mountains?
The Scientific Method:
The Scientific Method:
Is a new way of thinking.
“Straight form the horse’s mouth.”
The Scientific Method:
Is a new way of thinking.
It may not be the best way, but it is very pragmatic
and produces immense amounts of information.
Deduction
From the general to the specific. A "top-down" approach.
1.
2.
3.
4.
Create a theory.
Create specific hypotheses that can be tested.
Collect observations to address the hypotheses.
Confirm with data
Deduction
From the general to the specific. A "top-down" approach.
Note:
That deduction starts with an IDEA, which leads to a logical test,
that then demands evidence from the world.
Note also:
How much faith you must put in your mind’s ability to reflect “reality.”
Induction
From the specific to the general. A “bottom-up" approach.
1. Specific observations and measures.
2. Identify patterns and regularities.
3. Formulate some tentative hypotheses that we can be explored.
4. Developing some general conclusions or theories.
Induction
From the specific to the general. A “bottom-up" approach.
Note:
That induction starts with an evidence from the world, which
leads to a logical test,
that then must meet the demands of logic.
According to psychologists, we do this almost automatically,
but we usually do it wrong.
Fundamental Attribution Error
Both Student 1 and Student 2 got a grade on the
same test.
Student 1 got an A. Student 2 got a C.
Student 1 says, “I got an A.”
Student 2 says, “The teacher gave me a C.”
Fundamental Attribution Error
The ideas that create the scientific method came from
the medieval and Renaissance beginnings…
1. Natural phenomena should be explained in terms of causes.
The ideas that create the scientific method came from
the medieval and Renaissance beginnings…
1. Natural phenomena should be explained in terms of causes.
2. Natural phenomena can be explained only as the effects
of natural causes only.
Adelard of Bath 1080 - 1152
Adelard of Bath, who was a very religious man, stated in 1116 AD.
“I am not slighting God’s role, for whatever exists is from him and
through him. Nevertheless, that dependence is not to be taken in
blanket fashion without justification.”
The ideas that create the scientific method came from
the medieval and Renaissance beginnings…
1. Natural phenomena should be explained in terms of causes.
2. Natural phenomena can be explained only as the effects
of natural causes only.
3. Knowledge must be based on direct experience or repeatable
experiments, not authority.
The ideas that create the scientific method came from
the medieval and Renaissance beginnings…
1. Natural phenomena should be explained in terms of causes.
2. Natural phenomena can be explained only as the effects
of natural causes only.
3. Knowledge must be based on direct experience or repeatable
experiments, not authority.
4. Mathematics is the proper “language” to describe nature.
Mathematics has something
to do with reality!
Pythagoras
570 BC – 495 BC
A blackbody is defined as an object that absorbs incoming radiation and
emits energy at full efficiency for all wavelengths.. The following equation is
used to calculate the magnitude of this wavelength dependent radiation.
Back to the problem of knowing….
Since all experience of the world outside
our brains is
perceptual…
How can we know what is true?
Bacon maintained that the mind was
the problem with knowing because
we misperceive reality…
Therefore, we must use a “mechanical”
method to obtain empirical data…
Strictly controlled by induction.
Francis Bacon
1561 - 1626
Descartes maintained that the mind was
the solution with knowing because the
mind reflected reality…
Therefore, we must use mathematics
as the key to knowledge…
Strictly controlled by deduction.
Rene Descartes
1596 - 1650
There is a fundamental problem with using
experiments to validate knowledge.
“Affirming the Consequence”
Affirming the consequent is a formal fallacy committed by reasoning in the form:
1. If P, then Q.
2. Q.
3. Therefore, P.
An argument of this form is invalid, i.e., the conclusion can be false even when
statements 1 and 2 are true. Since P was never asserted as the only sufficient
condition for Q, other factors could account for Q (while P was false).
http://en.wikipedia.org/wiki/Affirming_the_consequent
The planet Neptune was discovered by
applying Newton’s theory of gravitation
mathematically…
Does this mean then that Newton’s
concept of space and force are true?
Isaac Newton
1643 - 1721
Scientific Method
Refers to techniques for investigating phenomena and
the gaining of new knowledge, as well as correcting
and integrating previous knowledge, based on
observable, empirical, measurable evidence,
and subject to laws of reasoning.
Knowledge Avaliable
200
180
160
Measure
Knowledge
140
120
100
80
60
40
20
0
6000
4750
3500
2250
Years Before Present Time
1000
Basic Characteristics:
Basic Characteristics:
1.Descriptive
a. Public
b. Replicable
c. Reliable
d. Valid
Basic Characteristics:
1.Descriptive
2.Predictive
a. Past – Present – Future
b. Not interested in “one-shot” ideas
Basic Characteristics:
1.Descriptive
2.Prediction
3.Control
Basic Characteristics:
1.Descriptive
2.Prediction
3.Control
4.Understanding
a. Identification
b. Relationships
c. Cause-effect
Assumptions:
Assumptions:
1.Empiricism
a. “Look and see”
Assumptions:
1.Empiricism
a. “Look and see”
b. All hypotheses and theories are in
principle subject to disproof.
Comment of professor: “People may begin to disbelieve scientists.”
Deduction….
deduce
Induction
Problem with induction…
“The problem, in basic
terms, can be understood
by example: given that the
sun has risen every day for
as long as anyone can
remember, what is the
rational proof that it will rise
tomorrow?”
http://en.wikipedia.org/wiki/Karl_Popper
Popper, then, repudiated induction, and
rejected the view that it is the characteristic
method of scientific investigation and
inference, and substituted falsifiability in its
place.
Every genuine scientific theory then, in
Popper's view, is prohibitive, in the sense
that it forbids, by implication, particular
events or occurrences. As such it can be
tested and falsified, but never logically
verified.
http://plato.stanford.edu/entries/popper/#CriEva
Assumptions:
1.Empiricism
2.Determinism
a. There is a cause for any given effect.
B. F. Skinner argued that there was no
such thing as free will…..
Every person does what his or her
environment demands.
Remember: There has to be a
cause for every effect!
B. F. Skinner argued that there was no
such thing as free will…..
Every person does what his or her
environment demands.
An iron ball…
An iron ball…
A rat ball…
An iron ball…
A rat ball…
A live rat…
Assumptions:
1.Empiricism
2.Determinism
3.Parsimony
a. The simple explanation is usually best.
Assumptions:
1.Empiricism
2.Determinism
3.Parsimony
4.Testability
a. All ideas and hypotheses must be testable.
Procedure:
Procedure:
1.Observation
Procedure:
1.Observation
2.Development of a hypothesis
Hypothesis: “underlying idea or proposition”
Procedure:
1.Observation
2.Development of a hypothesis
3.Make a prediction
Procedure:
1.Observation
2.Development of a hypothesis
3.Make a prediction
4.Test prediction
Procedure:
1.Observation
2.Development of a hypothesis
3.Make a prediction
4.Test prediction
5.Start over
Scientific Method
1. Observation
2. Hypothesis
3. Test
1. Observation
2. Hypothesis
3. Test
1. Observation
2. Hypothesis
3. Test
Is acetaminophen better than a placebo?
Example:
Evaluations of Teaching
Example:
Evaluations of Teaching
What does the student evaluation actually measure?
Does it measure students or instruction?
Mean Expected and Deserved Grades
Over the Term
3.6
Initial Eval
Deserved
Expected
Eval
Final
Grade Average
3.4
3.2
3
2.8
2.6
W0
W2
W4
W6
W8
W10
Week of Term
W12
W14
W16
Mean Expected and Deserved Grades
Over the Term
3.6
Initial Eval
Deserved
Expected
Eval
Final
Grade Average
3.4
3.2
3
2.8
2.6
W0
W2
W4
W6
W8
W10
Week of Term
W12
W14
W16
Mean Expected and Deserved Grades
Over the Term
3.6
Initial Eval
Deserved
Expected
Eval
Final
Grade Average
3.4
3.2
3
2.8
2.6
W0
W2
W4
W6
W8
W10
Week of Term
W12
W14
W16
Mean Expected and Deserved Grades
Over the Term
3.6
Initial Eval
Deserved
Expected
Eval
Final
Grade Average
3.4
3.2
3
2.8
2.6
W0
W2
W4
W6
W8
W10
Week of Term
W12
W14
W16
Direct and Indirect Effects of
Rigor and Personality
0.834
Evaluation
-0.125
0.418
Learning
-0.042
0.461
Instructor
0.003
Legend
Personal
Rigor
0.199
Fair
-0.534
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Mean Expected Grade and
Grade Deserved
3.5
3.4
3.3
3.2
GPA
3.1
3
2.9
Legend
Exp Gr
Deserved
2.8
2.7
0
2
4
6
8
10
12
Week of Semester
Last Mean at Week 17 is Actual Course Grade
14
16
Mean Expected Grade and
Grade Deserved
3.5
3.4
3.3
3.2
GPA
3.1
3
Legend
Exp Gr
Deserved
Inst
2.9
2.8
2.7
0
2
4
6
8
10
12
Week of Semester
Last Mean at Week 17 is Actual Course Grade
14
16
Mean Expected Grade and
Grade Deserved
3.5
3.4
3.3
3.2
GPA
3.1
3
Legend
Exp Gr
Deserved
Eval
2.9
2.8
2.7
0
2
4
6
8
10
12
Week of Semester
Last Mean at Week 17 is Actual Course Grade
14
16
Mean Expected Grade and
Grade Deserved
3.5
3.4
3.3
3.2
GPA
3.1
3
Legend
Exp Gr
Deserved
Personal
2.9
2.8
2.7
0
2
4
6
8
10
12
Week of Semester
Last Mean at Week 17 is Actual Course Grade
14
16
Mean Expected Grade and
Grade Deserved
3.5
3.4
3.3
3.2
GPA
3.1
3
Legend
Exp Gr
Deserved
Like
2.9
2.8
2.7
0
2
4
6
8
10
12
Week of Semester
Last Mean at Week 17 is Actual Course Grade
14
16
More Formal:
1. Define the question
2. Gather information and resources
3. Form hypothesis
4. Perform experiment and collect data
5. Analyze data
6. Interpret data and draw conclusions that serve
as a starting point for new hypotheses
7. Publish results
More Formal:
1. Define the question
2. Gather information and resources
3. Form hypothesis
4. Perform experiment and collect data
5. Analyze data
6. Interpret data and draw conclusions that serve
as a starting point for new hypotheses
7. Publish results
A retail store is loosing sales on Saturday afternoon.
Why?
Reference and Citation
The scientific method requires
that information be researched
and that all sources be cited and
referenced
http://jmd.sagepub.com/content/35/1/26.full.pdf+html
Topic:
History
History:
1. Spiritual Animism
History:
1. Spiritual Animism
History:
1. Spiritual Animism
2. Early Science
History:
1. Spiritual Animism
2. Early Science
Message runner who drank ginseng tea
could run further and faster.
Design an experiment
to see what ginseng
will actually do.
History:
1. Spiritual Animism
2. Early Science
3. Tradition
Something happened about here:
Descartes wrote:
Rene Descartes
(1596 – 1650)
“Our inquires should be directed
not to what others have thought,
not to what we ourselves conjecture,
but to what we can clearly
and perspicuously behold
and with certainty deduce;
for knowledge is not won in any other way.”
History:
1. Spiritual Animism
2. Early Science
3. Tradition
4. Scientific
History:
1. Spiritual Animism
2. Early Science
3. Tradition
4. Scientific
5. Modern Science
Causality:
How do we know if A caused B?
B
A
Causality:
How do we know if A caused B?
1. Concomitant Relationship
a. There is a correlation between A and B
Causality:
How do we know if A caused B?
1. Concomitant Relationship
a. There is a correlation between A and B
A
B
Causality:
How do we know if A caused B?
1. Concomitant Relationship
2. Causal Order
a. A happened before B
Causality:
How do we know if A caused B?
1. Concomitant Relationship
2. Causal Order
3. Elimination of Alternatives
a. Can all other explanations be explained
and controlled?
Approaches to the Truth:
Approaches to the Truth:
1. Logical reasoning (philosophy)
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (religion/meditation)
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (Religion/meditation)
3. Factual observation (science)
Poverty Rates
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (Religion/meditation)
3. Factual observation (science)
Which is better?
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (Religion/meditation)
3. Factual observation (science)
Which is better?
Remember: Just because a theory works,
does not prove that it is true.
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (Religion/meditation)
3. Factual observation (science)
It depends!
Generally factual observation is usually best.
Approaches to the Truth:
1. Logical reasoning (philosophy)
2. Awareness and revelation (Religion/meditation)
3. Factual observation (science)
It depends!
Generally factual observation is usually best.
Best it is not always the best…
Generally factual observation is best.
But it is not always the best approach.
Quantum physics is not logical, but it was
discovered by logic
(thought problems and Math).
Wermer Heisenberg
1901 - 1976
Generally factual observation is best.
Doctor who prayed and meditated in a temple
every morning before seeing patients.
Galileo Galilei
1564 - 1642
Galileo was found "vehemently suspect of heresy", by stating that the Sun
is motionless and at the center of the universe, and that the Earth moves,
contrary to Holy Scripture.
He was required to "abjure, curse and detest" those opinions.
What does this tell us?
1882 - 1981
"Ideas without precedent are generally looked upon with
disfavour and men are shocked if their conceptions of an
orderly world are challenged."
Uniformitarianism
Uniformitarianism is the assumption that the same natural
laws and processes that operate now, have always operated in
the universe in the past and apply everywhere in the universe.
It is gradualistic in that what happens now can generally be
thought of as functioning at the same rates in the past.
It was a key principle of geology and virtually all fields of
science.
In the 1920’s. geologists literally set up an ambush for Bertz,
and it wasn’t until the 1950’s that his ideas began to be
widely accepted.
http://www.detectingdesign.com/harlenbretz.html
Richard Feynman
1918 - 1988
“You must not fool yourself and
you are the easiest person to fool.”
And the smarter you are, the easier
it is to fool yourself.