Changes

In many epidemiological studies, it is not possible to include every individual in a population. Rather, a [[Sampling strategies|sample]] of individuals is collected. This may be take the form of a [[Study design#Surveys|survey]], a [[Study design#Cross sectional studies|cross-sectional study]], a [[Study design#Experimental studies|randomised controlled trial]], and so on. The important issue is that '''not every individual in the [[Sampling strategies#Source population|source population]] is included, which means that [[Random error| random, or sampling, error]] and [[Bias|biases]] may be introduced.

In many epidemiological studies, it is not possible to include every individual in a population. Rather, a [[Sampling strategies|sample]] of individuals is collected. This may be take the form of a [[Study design#Surveys|survey]], a [[Study design#Cross sectional studies|cross-sectional study]], a [[Study design#Experimental studies|randomised controlled trial]], and so on. The important issue is that '''not every individual in the [[Sampling strategies#Source population|source population]] is included''', which means that [[Random error| random, or sampling, error]] and [[Bias#Selection bias|biases]] may be introduced. These affect our ability to extrapolate our results (whether [[Study design#Descriptive studies|descriptive]] or [[Study design#Analytic studies|analytic]] in nature) to the source population. However, the aim of most studies is to draw some conclusion about the source population, using the results obtained from the sample. This is known as '''inferential statistics''', and is a very important concept.<br>

[[Category:Veterinary Epidemiology - Statistical Methods|D]]

[[Category:Veterinary Epidemiology - Statistical Methods|D]]