Experimental Design in "Scaleless Snake"

Independent Variables
 What scientists manipulate
 Presence or absense of scales
(in this case "nature" performed
the "manipulation")
Dependent Variables

 What is measured
(that affects our conclusions
about the hypothesis)
 Water Loss
Heat Transfer
Standardized Variables

 What is kept the same
 Surface Area
Metabolism / Oxygen Consumption

(what is standardized in "scaleless snake"
is also measured but measured to insure
that each of these variables has the same
influence on the snake with scales as on
the snake without scales)
Experimental Treatment(s) Those treatments where the
independent variable is manipulated
from its normal/baseline state

Snake without scales

(it is essential to compare the experimental treatment
with one or more control treatments in order
to determine if there is an effect of
manipulation of the independent variable)
Control Treatment(s)

Those treatments where the
independent variable is in its
normal/baseline state

Snake with scales

(sometimes there are two types of controls -
positive and negative - that serve
as baselines for two extremes for
the response of the dependent variable
to manipulation of the independent one)

The table above lists most of the important variables in the "scaleless snake" experiment and illustrates their relationship. When you summarize an original article, try to decide what relationship the variables have to each other. This relationship will help you to understand the purpose of the research and can guide you in knowing which procedures you should emphasize in the methods section of your summary. Not all procedures described in the original are of equal importance. Your summary should report on those that have the most effect on the overall purpose of the research.