Just as a thought, but I recall back when I was at school (17 years since I finished high school) we did a project which involved surveys. I remember we worked in teams of four and my team got extra credit for including obviously 'wrong' answers, and explaining how we had allowed for them in our analysis and conclusion. In any survey, some will take delight in giving you garbage, but good data analysis means you don't ignore them, or sweep them under the carpet. You still account for them in your work.
And, in answer to Hawker's questions:
1. How old are you? 33
2. How many models on average do you buy a month? Varies - sometimes 2 or 3 in a month, then there may be a couple of months where I buy. Depends what I need at the time.
3. What scale do you prefer to use? 00
3. How much would you be willing to pay for an average sized model? Again depends on how it meets my needs at the time. I've never spent more than £30 in a single purchase.
4. How long would you spend on making an average sized model? Again, not easy to answer - they are a labour of love and take as long as they take to get right. Last model I made represented about 30-hours work on total from preparation, to construction, to painting. That 30 hours or so took four weeks of my spare time though.
5. Which material do you prefer to work with? I use a lot of polystyrene, balsa wood, matchsticks, occasionally vacuum-form plastic. Not very much metalwork but I've done some.
6. Do you buy models from shops or from the internet? Usually model shops as I like to see what I'm buying.
7. What theme of model railway are you most interested in? End of steam to childhood memories for me so it's pretty much 1960's to late 1980s.
Hope this is helpful and good luck with the work.
