Microsoft Word research method fm doc

Particular features of the exposure and disease. 
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Logistic considerations of available resources. 
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Results from previous studies and gaps in knowledge that remain to be filled. 
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Ingenuity and creativity of the researcher 

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Research methodology 
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Summary 
Individuals
. case reports 
Descriptive studies
. case series 
 
. cross-sectional 
Populations
. ecological 
(correlational) 
 
. comparative
cross-sectional 
Analytic studies observational studies
. case- control
. cohort 
Experimental studies
. therapeutic trials 
. preventive trials 
6.4 Study population 
At an early stage in the planning of any investigation decisions must be made concerning the 
study population. That is, concerning the population of individual units (whether they are 
persons, households, etc.) to be investigated. The population under consideration should be 
clearly and explicitly defined in terms of place, time, and other relevant criteria. If the study 
population comprises cases of a disease the procedures to be used for case identification 
should be stated. If controls are to be chosen their method of selection should be stated.
Often the investigator will have implicitly chosen his study population when he defined the 
topic of his investigation, by reason of his interest in a specific community or a specific health 
program.
In other instances, particularly when an analytic survey or an experiment is being planned, 
the investigator may require purposively to select a study population. In so doing he must 
consider questions of appropriateness and practicability.

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Research methodology 
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The appropriateness of the study population refers to its suitability for the attainment of the 
objectives of the study.
The selection of study population on the basis of suitability usually affects the validity of 
subsequent generalizations from the findings. This situation requires a close attention at the 
early stage of the given study. Two examples are given below. 
a) Volunteer populations: Persons who volunteer to enter a study may differ in many 
respects from those who do not so volunteer, and therefore the findings in a volunteer 
population do not necessarily apply to the population at large. 
b) Hospital or clinic populations: Persons receiving medical care are obviously not 
representative of the general population from which they have come from. That is, 
persons treated in hospital for a certain disease may differ from those patients with the 
same disease but not receiving care for it.