Note: The above
diagragm and the following text were copied from http://physics.ucr.edu/~wudka/Physics7/Notes_www/node6.html
The scientific method is
the best way yet discovered for winnowing the truth from lies and
delusion. The simple version looks something like this:
·
Observe some aspect of the
universe.
·
Invent a tentative
description, called a hypothesis, that is consistent with what
you have observed.
·
Use the hypothesis to make
predictions.
·
Test those predictions by
experiments or further observations and modify the hypothesis in the
light of your results.
·
Repeat steps 3 and 4 until
there are no discrepancies between theory and experiment and/or
observation.
When consistency is
obtained the hypothesis becomes a theory and provides a
coherent set of propositions which explain a class of phenomena. A
theory is then a framework within which observations are explained and
predictions are made.
The great
advantage of the scientific method is that it is unprejudiced: one does not have to
believe a given researcher, one can redo the experiment and determine
whether his/her results are true or false.
What is the scientific method to an epidemiologist?
"The
systematic collection and analysis of data involves the determination
of whether a statistical association exists--in other words, whether
the probability of developing a particular outcome in the presence of
a given factor or exposure is different from the corresponding
probability in its absence. It is then necessary to assess the
validity of any observed statistical association by excluding possible
alternative explanations, such as the luck of the draw (chance),
systematic errors in collecting or interpreting data (bias), as well
as the effects of additional variables that might be responsible for
the observed association (confounding). Finally, a judgment is made as
to whether the statistical association represents a cause-effect
relationship between exposure and disease. Such a judgment requires
inferences far beyond the data from any single study and involves
consideration of criteria that include the magnitude of the
association, the consistency of findings, from all other studies, and biologic
credibility." [Epidemiology
in Medicine]
What is evidence-based medicine (EBM) to a psychiatrist
who does research?
"In
my reading of EBM, the basic idea is that we need to understand what
kinds of evidence we use, and we need to use the best kinds we can:
this is the concept of levels of evidence. . . . The basic
constant idea is that randomized studies are higher levels of evidence
than non-randomized studies, and that the lowest level of evidence
consists of case reports, expert opinion, or the consensus of the opinions
of clinicians or investigators. . . . This does not mean that such
evidence [the lowest level] is wrong, nor does it mean that it is not
evidence; it is a kind of evidence, just a weak kind." [Ghaemi]
What is the scientific method for the Institute of
Healthcare Improvement?
"Once a team has set an aim, established its
membership, and developed measures to determine whether a change leads
to an improvement, the next step is to test a change in the real work
setting. The Plan-Do-Study-Act (PDSA) cycle is shorthand for testing a
change — by planning it, trying it, observing the results, and
acting on what is learned. This is the scientific method, used for
action-oriented learning." [Institute
for Healthcare Improvement]
A discipline to discover the truth requires iteration (repeated
trials) and consistency.
Iteration is “a procedure in which repetition of a sequence of
operations yields results successively closer to a desired result.” [Merriam-Webster
Dictionary] Given the motive to find the truth, the scientific method is driven
by iteration and testing for consistency in physics, epidemiology,
organizational improvement, and drawing a map of the knowledge domain of
occupational hazards and diseases.