accuracy The degree to which a measurement or an estimate based on measurement represents the true value of the attribute being measured. Not to be confused with precision or validity.
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"accuracy" A Dictionary of Public Health. Ed. John M. Last, Oxford University Press, 2007. Oxford Reference Online. Oxford University Press. Copenhagen University Library. 13 February 2008 <http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t235.e25>
precision In measurements, the quality of being exact or sharply defined. A measurement of length to decimal places of millimeters is more precise than a measurement to the nearest meter. Precision or exactness must be distinguished from accuracy, i.e., conformity to the true or real value.
How to cite this entry:
"precision" A Dictionary of Public Health. Ed. John M. Last, Oxford University Press, 2007. Oxford Reference Online. Oxford University Press. Copenhagen University Library. 13 February 2008 http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t235.e3615
validity The extent to which a measurement actually measures what it purports to measure or an entity actually is what it purports to be. There are several kinds of validity. Criterion validity is the extent to which a measured variable or an entity correlates with an external criterion of the phenomenon under study. This has two aspects: concurrent validity means that the measurement and the criterion refer to the same time and place; predictive validity is the ability to predict the criterion. Construct validity is the extent to which measurements conform to theoretical concepts or constructs. Content validity is the extent to which measurements incorporate the domain of the phenomenon under study. Study validity is the degree to which the inferences from a scientific study are warranted, taking into account the strengths and weaknesses of the study design. This has two aspects: internal validity, the degree to which observations may be attributed solely to the hypothesized effect that is being studied, and external validity, which is the extent to which the findings of a study can be generalized.
How to cite this entry:
"validity" A Dictionary of Public Health. Ed. John M. Last, Oxford University Press, 2007. Oxford Reference Online. Oxford University Press. Copenhagen University Library. 13 February 2008 <http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t235.e4676>
