By the end of your edit you’ll be over familiar with your film, maybe a bit tired and will probably not be able to make a good judgement of whether it’s working or not. It’s a natural occurrence and nearly all filmmakers use ‘test’ audiences as guinea pigs. Some go to greater lengths than others, but the least you can do is get a couple of friends in who will be honest with their appraisal.
The best test viewer is one that knows nothing about the film. Don’t test on actors or crew from the film, they’ll be looking out for their best bits!
It’s good to have a mixed range of people too, some might be film fanatics but others not so. Then you get the broadest reactions.
Don’t tell your audience too much before the film, certainly not any vital information that is supposed to come out naturally in the film. When you’ve finished screening, don’t ask leading questions. Audiences can find it hard to be honest with questions like these. Let them speak their mind, it’s amazing how the simplest comment can have a huge impact.
Take every comment with a pinch of salt. Unless it’s a unanimous decision, don’t go and make every single change that somebody comments on.
And remember, the editor will quite often know ways of fixing problems that crop up in test screenings without resorting to the suggested solutions.