In so many discussions, people keep discussing about data and meta data. So one starts wondering what is meta data?
Well, meta data is data about data.
Because of several discussions with my respected (and very well known) researcher friends I am forced to ask and discuss the following questions:
1. Why do we need meta data?
2. Is data and meta data are really different or are they context dependent.
To me all data is data. Depending on what you are trying to analyze and understand, the role changes. Lets consider a simple example. I am carrying a camera and a GPS device that tells my location. I note the data stream from the GPS indexed by time and also note the phot stream indexed by time. Is GPS stream data or meta data? Is phot stream data or meta data?
Suppose I am interested in finding what I saw when I was at a particular location then which one is meta data and which is data? Here emphasis is on the location and what I saw there is just metadata. On the other hand if I store GPS as EXIF attribute in my photo file then my photo becomes the data and location becomes the metadata.
More relevant to analysis, one is given multiple correlated data streams. They are all just data streams. At any given instance in analysis, one focuses on a particular stream and calls it data and at that point, every thing else becomes metadata. But this role keeps changing as the focus in analysis changes.
It will help my researcher friends if they started considering all data to be the same — as data. Ultimately, we learned much more about the physical world when we started thinking in terms of atoms and molecules. We will understand data much better when we start consiering data interms of bits and bytes.