The various types of data aggregation and what we call them has been a topic in several RDA groups. "Data set/dataset" or "Digital Collection" and "data series" are a few of the frequently used terms. In the DFT WG snapshot document we had an initial definition of "Digital Collection" as:
A digital collection is an aggregation which contains DOs and DEs. The collection is identified by a PID and described by metadata.
Note: A digital collection is a (complex) DO.
Note: A digital collection is an aggregation in so far as there are other types of aggregations.
There was probably too little discussion of this and related concepts and so I have tried to continue the conversation with relevant people and groups.
A recent was with Reagan Moore who provided some ideas (perhaps from a policy point of view) as below. I thought that it might serve as a basis for more conversation.
1. Reagan "Digital collections implement arrangement by a community for organizing their digital entities."
Gary comment - this makes the point that aggregations serve community needs and thus will vary. There may then not be external labels for all of these types of arrangements. Maybe the best we can do is to have some broad categories into which different types of arrangements fit.
2 Reagan "Data series is used by NARA to define the sequence of records archived by a federal agency under a submission agreement control."
Gary comment - I like this as a way of grounding ourseleves in a authoritive source, the NARA, as a basis of data series. They merely add a time dimension to files and digital sets. But does this work for everyone and if not how would their definition different from NARA's? See http://smw-rda.esc.rzg.mpg.de/index.php/Dataset_series for our attempt as part of DFT WG.
3. Reagan "A data series is also used to denote the sequence of data received from a sensor."
Gary discussion - This introduces a more specific type of data series - a "sensor-based data series."
4. Regan "A data set nominally identifies a discrete set of digital entities."
Gary comment -We might need to explain that arrangement basis for the "discrete set." Not how many alternate idea on dataset we had when discussing this
in DFT WG see http://smw-rda.esc.rzg.mpg.de/index.php/Data_Set
5. Regan "A data stream denotes the sequence of data received from a sensor."
Gary comment - We did no have the sensor as source in our working defintion but this was perhaps included or implied in the context of messaging. see http://smw-rda.esc.rzg.mpg.de/index.php/Data_Stream
Comments on the above idea would be appreciated.