Bottom Content goes here.
Wikipedia content requires these links.....
Wikipedia content is licensed under the GNU Free Documentation License.
Planning statistical research
Most scientific work starts with a question about the world we live in. For
a statistician, these questions can be classified into a few different kinds.
1. We can start with questions about a single Unit, like a biological
organism, a manufactured product, a plot of ground, a city block or any
of many different things we want to understand. In this type of study,
we are often concerned with the dynamics of the Unit; how does it vary
in time? Can we identify what aspects seem to control others? (See
2. Sometimes, our interest in a Unit may be purely instrumental, that is,
we are interested in the Unit because of a population to which it
belongs or an environment in which it resides. Our desire to describe a
population may be satisfied by a statistical report on a sample from
that population. The methodology is to select a sample and observe just
the Units which are selected and then to summarize our results and
interpret their meaning for the population. When we deliberately
manipulate something in the process of observation, we call it an
experiment. When we attempt to observe the Units without affecting
them, we call it a survey.
3. Sometimes, we want to understand the internal workings of a Unit so we
look at its components and how they relate to each other. Physiology is
an example of a discipline in which this kind of focus is common.
In much research, we use all three modes at different stages. A useful
synthesis of this kind of thinking was provided by Ludwig von Bertalanffy.
In every type of research, we must be concerned with managing the
observational error that is inherent in all empirical research. We can
increase the precision of our research by
1. using a more precise instrument (eg., a more powerful telescope)
2. increasing the number of observations so the constant we try to measure
stands out better against the noise.
3. changing the design of our research. This last approach can become very
technical, so we will postpone its discussion until optimum