Point:
"Scientists Important are critical realists. John Polkinghorne
"Science is properly described as organized
skepticism, a realm in which nothing is to be
accepted without question. Philip W. Anderson
nevertheless, and probably quite accurately,
Margaret Wertheim replies with: "Science has
always had a huge component of faith."
This latter statement reflects the idea that ultimately
not everything (nothing?) can be proven to
100% confidence; A good scientist
nevertheless allows that even those things she
accepts on faith could very well be incorrect
Models are
abstract
representations
of ideas; they
can be visual,
mathematical,
experimental,
etc., but are
always simpler
than the they
system they are
purporting to
model
Science, A Few More Ideas
"...science is simply common sense at its best; that
is, rigidly accurate in observation and merciless to
fallacy in logic." Thomas Henry Huxley, 1880
"scientists are not a select few intelligent enough to think in
terms of broad sweeping theoretical laws and principles.
Instead, scientists are people specifically trained to build
models that incorporate theoretical assumptions and empirical
evidence. Working with models is essential to the
performance of their daily work; it allows them to construct
arguments and to collect data." Peter Imhof
"Science is [best] understood by observing it than by trying to
create a precise definition. The word science is derived from
a Latin verb meaning to know. Science is a way of knowing.
It emerges from our curiosity about ourselves, the world, and
the universe. Striving to understand seems to be one of our
basic drives. At the heart of science are people asking
questions about nature and believing that those questions are
answerable." your text (older edition)
At the heart of science is Inquiry, a search for
information and explanation, often focusing on
specific questions. Campbell and Reece (2005, p. 19)
Doing Science
A Scientific Model
What is Science?
Chapter 1b:
Exploring Life
(section 1.5)
Doing science involves:
Asking good questions
Coming up with good, plausible answers (a.k.a.,
hypotheses)
Testing these hypotheses robustly,
unambiguously, and honestly (the latter from the
point of view of both yourself and that of others)
"Science is a creative human endeavor that involves
asking questions, making observations, developing
explanatory hypotheses, and testing those
hypotheses. your lab text
It is "important for you to learn, by example and by
practice, how the process of science works." your text
"Anyone going into biology expecting to find the sorts
of exceptionless laws that characterize physics will be
sorely disappointed." Ernst Mayr
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Succeeding in Science
"Success in science is rewarded with attention. You gain
full membership in the scientific community only by
receiving the attention of your fellow scientists. Earning
this attention income is a prime motive for becoming a
scientist and for practicing science. In order to
maximize this income, you have to employ your own
attention in the most productive way. It does not pay
to find things out anew that have been discovered already.
Nor is reinvention rewarding in terms of the attention
paid. It pays to pay attention to the work done by others."
Georg Franck
In school, doing science well is rewarded with good
grades in science classthe same skills that allow one to
do science well will allow one to succeed in biology
class: learning, understanding, synthesis, an ability to
communicate your thoughts well, etc.
Questions Addressed
Time-Wasting Avoidance
Asking Good Questions
Doing Science
Questions Addressed
What questions do scientists tend to address?
More often than not the questions that are addressed
first are those perceived to be both potentially
fruitful and less difficult to answer
For some questions science is willing to invest
enormous amounts of resources (curing cancer,
creating weapons of mass destruction during
national military emergencies, etc.)
For other questions, science (or, more precisely,
funding agencies) are unwilling to invest many if
any resources
The basic questions come down to:
Is the endpoint worthwhile?
Are the resources necessary to solve the
problem in excess of the perceived worth?
Is the endpoint likely to be reached?
Science is a means of timing-wasting avoidance
Doing science poorly (or not doing science at
all) results in failing to answer questions
efficiently
Doing science poorly can result in wasting others
time (with poorly thought out hypotheses or results)
The cost of wasting the time of others is
ostracismnobody wants to have their time wasted
by incompetent boobs!
Nevertheless, often there is a fine line between
doing difficult science and wasting timethis is
one reason the easy-to-solve problems tend to be
solved sooner
The "open-mindedness" that non-scientists often
feel comes from lacking a well-developed
compunction to answer hard questions rigorously
(i.e., robustly, unambiguously, and honestly)
Is the endpoint worthwhile?
Are the resources necessary to solve the problem in excess of the
perceived worth?
Is the endpoint likely to be reached?
For conservative, applied research, using established
techniques, the answers generally are yes, yes, and yes
(even when the scientific questions aren't terribly interesting)
For speculative, basic, or extremely difficult research,
the answers can be no, no, no
Ultimately whether a question is pursued is a function
of the amount of resources a society is willing to
devote to science
The consequence is that science does not always work
toward its own goals with the efficiency it (or we)
would prefer
Wild card: questions (& means to answering
questions) that are interesting in their own right
Asking Good Questions
Forming Hypotheses
Testing Hypotheses
"Items investigated must be well defined,
measurable, and controllable. The questions should
be reasonable and consistent with existing bodies of
knowledge. [Individuals] have a variety of ways to
exclude wild speculations." your lab text
A good scientific question is one that may be
answered through experiment, observation, or
logical inference that is built upon previous
experimentation or observation
Beware of direct correlations vs. indirect correlations
(cause and effect vs. effect and effect)
Questions are also judged on the worth one or many
perceive to be associated with successfully answering that
question
2
Keep in mind that:
Hypotheses represent possible causes
They reflect past experience with similar questions
Multiple hypothesis should be proposed if possible
Hypotheses should be testable via the hypotheticodeductive approach
Hypotheses can be eliminated
But hypotheses cannot be confirmed with absolute
certainty
Note that in practice hypotheses are a dime a dozen
easy to propose, difficult to prove
Also, very few are sufficiently comprehensive nor stand
up sufficiently to the test of time and experimentation to
achieve the status of a theory
Qualitative Data
More on Hypotheses
Good Hypotheses
Asking Good Questions
Forming Hypotheses
Testing Hypotheses
Forming Hypotheses
Good vs. Bad Questions
"Does exposure to ultraviolet radiation cause
increased risk of skin cancer?"
"Does good nutrition lead to increased intelligence?"
"Why do cacti have spines?"
"Was the malignant tumor found in the lungs of a 70year-old man caused by his 45-year habit of smoking
cigarettes?"
Do good study habits result in good grades in science
classes?
Though these are all good questions, they are not
necessarily easy to answer, however...
Was Lee Harvey Oswald possessed by demons?
Bad question:
How do we define demon?
How do we determine whether L.H.O. was possessed
by one?
A hypothesis is a tentative answer to a
well-framed questionan explantion on
trial. It is usually an educated postulate,
based on past experience and the available
data of discovery science. Campbell &
Reece (2005), p. 20
A hypothesis tentatively explains
something observed. your lab text
It is a proposed answer to a scientific question
Asking Good Questions
Forming Hypotheses
Testing Hypotheses
A good hypothesis satisfies the following criteria:
It supplies a testable mechanism
It is not unnecessarily complicated (Ochams razor)
It conforms with existing knowledge
It is falsifiable
If something cannot be demonstrated to be incorrect
then it cannot be demonstrated to be correct
Hypotheses tend to gather favor if they could be but
havent been demonstrated to be incorrect
"The test of a hypothesis may include
experimentation, additional observations, or the
synthesis of information from a variety of sources."
your lab text
The term data
implies numbers
to many people.
But some data
are qualitative,
often in the form
of recorded
descriptions
rather than
numerical
measurements.
Campbell & Reece
(2005, p. 19)
3
Scientific Theories
Scientific Theories
A fact is what is witnessed upon observation
A scientific fact is only as good as the observer,
method of observation, and degree to which the
environment is sufficiently controlled during the
observation
Thus, facts are very fallible and must always be
considered suspect especially if they are contrary
to established theory and are not repeatable
under well-controlled conditions
In other words, extraordinary claims require
extraordinary proof
In the semantics of science, a fact does not have
explanatory or predictive powerone speaks of
hypotheses and theories as ways of organizing,
explaining, and extrapolating from facts
This is why a scientist speaks of the theory rather than
the fact of evolution
Scientific Law
A law is "a statement of order or relation
holding for certain phenomena that so far as is
known is invariable under the given
conditions Webster
In other words, a law, as far as we can tell, is
an infallibly robust hypothesis
In modern science it is considered reckless to
call a theory a law
Inductive Reasoning
Through induction, we derive generalizations
based on a larger number of existing observations.
Campbell & Reece (2005) p. 20
Inductive reasoning is associated with great ideas but not
necessarily very good experimental design
For example, Darwin's theory of evolution by natural
selection was achieved via inductive A reasoning: great
many observations were gathered and a unifying theme
was discovered
While inductive reasoning does not make for good
hypothesis testing, the results of inductive reasoning can
typically supply fertile ground for hypothesis making
Another word for inductive reasoning is synthesis
Synthesis, in general, is analogous to the more specific
synthesis observed in chemistry laboratories. That is,
synthesis is the build-up of a different whole from smaller
parts.
Scientific Reasoning
Scientific Facts
What is a theory and how is it different from a
hypothesis or from mere speculation?
First, a theory is much broader in scope than a
hypothesis
Second, a theory is general enough to spin off
many new, specific hypotheses that can be
tested
And third, compared to any one hypothesis, a
theory is generally supported by a much more
massive body of evidence
Those theories that become widely adopted in
science (such as the theory of natural selection)
explain a great diversity of observations and are
supported by an accumulation of evidence
All of the above is as quoted from Campbell & Reece
(2005), p. 24
A hypothesis becomes a theory following lots of
testing (i.e., attempted falsifications), all of which
fail to disprove the hypothesis
An important aspect of this testing is that it is done by
more than one (ideally by many) groups using more
than one (ideally many) independent techniques
In other words, a theory is a very robustly
supported hypothesis
Since, by definition, a theory has gone through
considerable criticism and attempted falsifications, it
is very unlikely that you or me or anyone we know or
admire is going to successfully demonstrate that a
well-established theory is false
E.g., Darwins Theory of Evolution (which in lay
language we would describe as a fact)
Asking Good Questions
Forming Hypotheses
Testing Hypotheses
A key aspect of doing science is the reasoning that goes
into the designing experiments, something that I'm
designating here as scientific reasoning
To test hypotheses you have to understand how to go
about scientific reasoning
There are two general categories of scientific
reasoning:
Inductive reasoning
Deductive reasoning
It is the latter that is usually employed in the course
of testing hypotheses and designing experiments
Inductive reasoning involves the gathering of
observations and hypotheses into a unifying whole
4
of a theory of evolution
that combined both
Darwinian evolution and
Mendelian genetics
Inductive Reasoning
Inductive Reasoning
An example of a synthesis
is the "Evolutionary
Synthesis" from the middle
of the twentieth century,
which involved the building
up, by inductive
reasoning
"Many people associate the word discovery with
science. Often, what they have in mind is the
discovery of new facts. But accumulating facts is
not really what science is about; a telephone book is
a catalog of facts, but it has little to do with science.
It is true that facts, in the form of observations and
experimental results, are the prerequisites of
science. What really advances science, however, is
a new idea that collectively explains a number of
observations that of course, Darwin to be
Except, previously seemed
unrelated. The most exciting ideas are those that
did discover a huge
explain the greatest variety of phenomenon. People
number of facts!
like Newton, Darwin, and Einstein stand out in the
history of science not because they discovered a
great many facts but because they synthesized ideas
with great explanatory power." your text (older ed.)
Deductive reasoning is an assumption of consistency
Deductive reasoning is the application of
generalizations to specific circumstances
This is hardly a profound statement; It simply means the
application of what we generally know to specific things
that we don't yet fully understand
More than anything else, introductory biology introduces
students to a sampling of the general themes of biology
With time you will learn to apply these themes to novel
situations to deduce explanations for novel observations
E.g., once you understand why lipids tend to not dissolve in
water, but that carbohydrates do, you will be able to look at
organic compounds that are new to you and make specific
predictions as to their water solubility
The process by which science typically progresses is
employing a mechanism known as Hypothetico-Deductive
Thinking
This fancy phrase basically means that one understands
new observations in light of previously learned or
subsequently looked up general knowledge, & then
phrases understanding as testable predictions
I.e., deductive reasoning hypothesis making
The catch, of course, is that not all knowledge is correct,
knowable, or even necessarily applicable to the new
observation
Furthermore, it isn't always obvious how to apply general
knowledge to new observations
When you have an interesting or important (and repeatable)
observation that cannot be explained in detail by current
scientific knowledge, what you have is the core of what I
would call an interesting scientific question.
Hypothetico-Deductive Thinking
Hypothetico-Deductive Thinking
Deductive Reasoning
Deductive reasoning is what biology is all about
5
Not Addressing Important Questions
Predicting the Future
Sometimes, when technologies and understanding
catch up with speculations, speculated hypotheses turn
out to be correct
Proposed future utility of a given hypothesis,
however, is no guarantee of present usefulness
An otherwise empty promise of future usefulness
should never be accepted instead of demonstrated
usefulness of a hypothesis in the present
This is why science fiction can be very cool but
nevertheless is still fiction
The only reasonable predictions of the future is
extrapolation from the past (i.e., that the future in
some manner will resemble the present)
This is the utility of science (and of history):
efficiently and accurately defining the present
and the past so as to predict the future
consequences of present trends and actions
Liberal vs. Conservative
Skepticism
Attitudes of skepticism derive from desires to
avoid wasting one's time on questions
perceived to be without significant usefulness
This is why the burden to answer questions
(demonstration of a lack of falsification of
hypotheses) is placed on proponents of ideas
rather than on the detractors
Extraordinary claimsone's not consistent
with an existing base of knowledge which so
far has stood the test of timetypically
demand extraordinary proof to be persuasive
Such proof is found in rigorous, robust, and
honest attempts at falsifying the hypothesis in
an unambiguous manner
Self Correction
Doing Science as Triage
A triage is a means of effort-wasting avoidance
In a wartime medical unit there are three types of
patients: (i) those who will survive without medical
intervention, (ii) those who will not survive even with
medical intervention, and (iii) those who will survive
but only given medial intervention
If you have the resources to deal with only a limited
number of patients, then you concentrate first on the
latter
What is being done is prioritizing
In science usually the first questions answered
are the most easily solved or most interesting
Less-easily solved questions or less-interesting
questions are solved next (if ever)
The least-interesting or most-difficult questions
tend to be addressed last (often never)
Scientific prioritizing is why questions that many
consider important (Why do we exist?) are typically
never considered by scientists
In a world of interesting, solvable problems, few
rational individuals commit enormous quantities of
time and energy to questions that are not readily
solved, no matter how interesting they may appear
Think about your own life When was the last time
you elected to attain world peace and prosperity
before dealing with more mundane concerns such as
eating lunch or voiding your bladder?
A bad scientific question typically is one in which the
ones potential to answer the question, even given
abundant technology and resources, is extremely
limited
For many hypotheses, existing technology and
understanding is not sufficient to supply such proof,
regardless of the efforts of proponents
Such hypotheses are generally discarded by other
scientists
In other words, scientists are typically skeptical of
claims that "fly in the face of reason," i.e., that are
inconsistent with what is already known scientifically
This is why scientists often come off as fairly
conservative in terms of their acceptance of new ideas
(a.k.a., have good B.S. meters)
They know how much work is required to test
hypothesesthat making hypotheses is far easier than
proving them
Scientists, consequently, are typically far more
interested in results of efforts to test hypotheses
than they are in the hypotheses themselves
"Another key feature of science is its progressive,
self-correcting quality. A succession of scientists
working on the same problem build on what has been
learned earlier. It is also common for scientists to
check on the conclusions of others by attempting to
repeat observations and experiments. Among
contemporary scientists working on the same
question, there [is] both cooperation and competition.
Scientists share information through publication,
seminars, meetings, and personal communication.
They also subject one another's work to careful
scrutiny. you text (older edition)
"In science seldom does a single test provide results
that clearly support or falsify an hypothesis. In most
cases the evidence serves to modify the hypothesis or
the conditions of the experiment." your lab text
6
The Tao of Self Correction
Self correction means that the testing of hypotheses is
typically repeated by others so long as a hypothesis:
Impacts on the work of others (i.e., is important)
Is plausible (i.e., people are willing to believe that
tests already performed could conceivable support the
hypothesis)
Is testable by other means
The End
Is contrary to other's previous understanding
Often if a claim is too outlandish then the burden
of proof will fall on the claimant, and others will
simply reject the claim; This is especially the case if
others don't consider the claim to be especially
important or plausible:
Look closely at claims of cold fusion? Yes!
Look closely at claims of perpetual motion? No!
7