Can anyone recommend any literature on how/why researchers select certain pieces of data for analysis (in the social sciences)????

How to use data, how to select stuff that is relevant, why certain data is used over others (so not just me choosing data, but also how other researchers use data) - that sort of thing

Sage has a really good handbook on qualitative research methods. Its got a 3rd edition out. Its a massive book, so not likely one you would want to purchase, but I would imagine a university library should have it or have access to it. Some of your questions on data selection might be linked to questions of methodology--e.g. what methodology you use may drive how you collect data. You did not mention if this was qualitative or quanitative, but even if its quanitative, the Sage handbook might have some helpful chapters for you, as they do have some discussion throughout on quanitative methods as well. Hope that helps.

Look at any books by 'David Silverman' (he's easy to read/understand, and is cited frequently by others ... also, you can use his texts to spin out to others - he gives suggestions in 'summary' sections).

Hope that helps.

what rsearch methods are you using?

Qualitative mainly, but some of the primary data is scientific(primarily quantitative) - guess I'm looking at how other researchers in my field have interpreted (or perhaps more accurately misinterpreted!) the scientific data

The scientific data is mainly based on simulations and predictions, so it isn't 'definate' IYSWIM