The Scientific Method (or process)
Today’s agenda:
1. Let’s hear your ideas: What did you come up with, and how?
2. How do scientists do their work? Variations on the process
3. Examination of written materials and on-line journals
The “classic” scientific method:
1) Pose a null and one or more alternative hypotheses
What do we mean by a null hypothesis?
Why does it matter that we are trying to test or falsify a null
hypothesis, rather than prove that it is true?
What are the implications of this “burden of proof”?
The “classic” scientific method:
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Pose a null and one or more alternative hypotheses
Conduct an experiment and record the data
Examine the data with statistical techniques
Reject the null hypothesis (with some risk of error),
Or, be unable to reject the null hypothesis and so have
to accept it as correct (with some risk of ).
There will be more about these forms of error later. For
now, remember that we are always estimating true
distributions and relationships, and acknowledgement of
the chance of making a mistake is an essential part of the
scientific method.
Experiments have two essential features:
What are they?
Experiments have two essential features:
1) Treatment and control
2) Replication
What about other forms of analysis and inference?
Do we always need to be erecting and falsifying hypotheses?
We might want to estimate the relative effect of different
processes on some complex outcome, rather than narrowly
determining whether each, in isolation, has an effect or not.
We might want to estimate the relative likelihood of a series
of possible outcomes, rather than just stating which is the
most likely to occur.
What about scientific approaches that do
not involve experimentation?
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Observation (animal behavior, environmental change, etc.)
Correlation (density and growth, salinity and survival, etc.)
Modeling (using the computer to explore scenarios, options)
Morphology (paleontology, etc.)
Measurements structured around some hypothesis
Microscopical examination (new pathogens, etc.)
Others?
I asked my colleagues here in SAFS for input into
how they do science. Here are some of their replies.
Interestingly, none used the word “experiment”.
From Ray Hilborn
As Thomas Huxley said "scepticism is the
highest of duties; blind faith the one
unpardonable sin".
I asked my colleagues here in SAFS for input into
how they do science. Here are some of their replies.
From Trevor Branch
I synthesize everything to try to understand the
whole. So given a topic, I read every paper I can
find, and gather all data sources together, and try
to talk to / email every key scientist in the field.
Then I write a review paper, write paper on what all
the data say together, or build a model to explain all
the data I collected.
I asked my colleagues here in SAFS for input into
how they do science. Here are some more replies.
From Tim Essington
I work by combining field observations with quantitative
models (often using a comparative approach in lieu of
experimentation), testing multiple hypotheses, to reveal
patterns in nature and likely drivers therein. Lately I've
been applying these approaches to study large (global)
scale patterns in fisheries and to evaluate ecological
responses to policy instruments.
I asked my colleagues here in SAFS for input into
how they do science. Here are some more replies.
From Bob Naiman
The essence of science as I practice it is "discovery". I try
to let an ecosystem (river, riparian zone or watershed)
tell me how it works ecologically to produce fish, retain
its long term vitality, and exhibit resilience to change. It is
the discovery, through research activities, that allow me
to tell a better and better "story" as time goes by. After
all, it is a good and accurate story that folks remember.
Where do we find scientific information?
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Peer-reviewed journals
Single-authored books
Symposia or other edited, multi-authored books
Master’s theses and doctoral dissertations
Agency reports
Websites and other electronic source
Others?
Each form of communication has strengths and weaknesses;
it is important to understand their differences.
Assignments for next class:
1) Think about your question further, and come
to class with a new or more focused statement
of the question.
2) Find a website or other public source of data
that pertains to the question. Be creative!
3) Go to the library (there are so many to choose
from!). Check out a book that is relevant to
the topic and bring it to class with you.
4) Read the book’s Chapter 1, pages 5-26
The books are lonely. Go to the
library, where they live, look at
them, open them, touch them, and
be glad that they exist. We are
lucky to have such a great library!