Here’s a useful (draft) set of colloquial definitions for Big, Open and Personal Data on GitHub from the Open Data Institute.
Why is this a worthwhile exercise? Well, Open Data gets conflated with Personal Data, everyone talks about Big Data (yet no-one is exactly sure what it is, but many have tried to define it)…and we all should be concerned about Personal Data.
1. Big Data is (i) data that you cannot handle with conventional tools or (ii) a term used as a vague metaphor for solving problems with data.
2. Open Data is data that anyone can use; without legal, technical or financial barriers.
3. Personal Data is data derived from people, where you can distinguish a person from other people in the group.
(also, can Big Open Personal (BOP) Data exist?)