In order to give you complete freedom the DET application can hold multiple sets of observations for the exact same survey (name and year). To accomplish this the DET introduces the concept of survey datasets
Each dataset contains all observations for a given survey. Each survey however, can have multiple datasets allowing you to import/export and merge surveys with ease.
You may for example keep the following datasets for the same survey (e.g. Services 2005):
The name of each dataset is user defined and can be chosen when a dataset is created. Each survey however, starts with a default dataset. Therefore a survey has always at least one dataset.
See also: