Design of Researchreferences:

R.A. Fisher: Design and Analysis of Experiments;HA29.F535

O. Kempthorne: The Design and Analysis of Experiments;HA29.K3

D.C. Montgomery: Design and analysis of experiments;QA279.M66

R.Mead: The Design of experiments: statistical principles for practical applications; QA279.M38

Dean, A. Design & Analysis of Experiments.http://site.ebrary.com/lib/ucalgary/Doc?id=5006012&ppg=21

Campbell, D. & Stanley, J. Experimental and quasi-experimental design for research.

Cook, T.D. & Campbell, D.T. Quasi-Experimentation: Design &Analysis for Field Studies.

Design of ResearchThe Lady Tasting Tea; a psycho-physical experiment

• Inductive inference is the only process known to us by which essentially new knowledge comes into the world.

• …inference from the particular to the general must be attended with some degree of uncertainty, but this is not the same as to admit that such inference can not be absolutely rigorous, for the nature and degree of the uncertainty may itself be capable of rigorous expression..

• …questions only of the right use of human reasoning powers, which all intelligent people, who hope to be intelligible are equally concerned, and on which the statistician, as such, speaks with no special authority.

Design of Researchpurpose

Typically, an experiment may be run for one or more of the following reasons:

(i) to determine the principal causes of variation in a measured response,

(ii) to find the conditions that give rise to a maximum or minimum response,

(iii) to compare the responses achieved at different settings of controllable variables,

(iv) to obtain a mathematical model in order to predict future responses.

Observations can be collected from observational studies as well as from experiments,

but only an experiment allows conclusions to be drawn about cause and effect. For example,

consider the following situation:

Design of Researchvariance control

• Systematic [experimental] variance:independent variable selection

• Extraneous variance:blockingmatchingregression

• Error variance:randomizationreliability and generalizabilityG and D studies

Design of Researchvalidity [Campbell and Stanley]

• Internal validity:history, maturation, testing,

instrumentation, statistical regression, experimental mortality, selection, selection-maturation interaction;

• External validity: reactive or interaction effect of testing, interaction effect, reactive effect.