Descriptive Data Analysis and Statistics
The two previous chapters have shown us the ways in which most data arise in Public Health. The first way passes through systematic recording in registers. There, data are usually measured and recorded for all units of the target population, for example for all consultations in the outpatient ward of the District Hospital of the district of Quynh Phu during the month of January 2018. The second way leads through sampling. Having drawn a sample of units from a given target population we are dealing with “sample data”. They are data that were measured and recorded only for the units in the sample, that is, in the study population. There also exist the unknown “population data” in the target population.