25 Statistical Principles

and Application in

Biopharmaceutical Research

Dan Anbar

25.1 The scientific method and

the role of the scientific

experiment

The purpose of science is to explain natural phe-
nomena by uncovering the natural laws that give
rise to them.
The scientific method is a three-step process: (a)
formulatingtheoriesasexplanationsofphenomena,
(b) making predictions based on these theories and
(c) testing the theories through experimentation.
Most people engage daily in the first two activities.
Explaining the environment in which we live is an
innate human urge. However, people rarely subject
their theories to testing by experimentation.
What makes the scientific method unique is that
it does not accept an explanation as valid until it has
been validated through testing. However, a scien-
tific experiment can neverprovea theory. At best, it
can provide evidence for the usefulness of the
theory in predicting the consequences of given
experimental conditions and help to define more
precisely the relationship between these conditions
and their consequences. The greatest value of a
scientific experiment is in its ability todisprovea
theory or identify limits of its applicability, either
of which is key to scientific advances. An experi-
mental finding inconsistent with a theory suggest

that a theory should be revised or rejected. Popper

(1959) states that a necessary condition for a valid

theory is the condition offalsifiability. That is, it

must be capable to generate predictions that can be

tested experimentally. Experimental outcomes

contradicting the theoretical predictions necessi-

tate a reassessment of the theory and lead to a

revision or rejection. In other words, a scientific

theory is always tentative and entirely dependent

on experimental verification. Theories that are not

falsifiable may be the subject of religious or philo-

sophical discourse but not of scientific investiga-

tion, according to Popper.

Experiments designed to confirm a theory (or to

falsify it) are called confirmatory, and those

designed to merely accumulate information and

generate hypotheses are termed exploratory.

Exploratory experiments are a useful first step in

the process of formulating scientific theories.

Either type must follow strict methodological pro-

cedures and adhere to a detailed experimental pro-

tocol describing the conditions of experimentation,

the methods of measurement and all other aspects

that might affect the results. The experimenter

must record the raw data prior to any analysis and

document any protocol deviations, documenting

all aspects of the experiment such that another

scientist can precisely repeat it.

Principles and Practice of Pharmaceutical Medicine, 2nd Edition Edited by L. D. Edwards, A. J. Fletcher, A. W. Fox and P. D. Stonier
#2007 John Wiley & Sons, Ltd ISBN: 978-0-470-09313-9