Thanks for the kind words and the very pertinent comment – screening is a great candidate for the 10th tip. I’ve found that being specific in the locations that you choose can do some of that work for you. For example, if you were looking at how people buy gadgets you might pop in to your local Student’s Union where you’ll find lots of people sporting or lusting after the latest gear. If you were evaluating a museum website you could sit in the museum’s restaurant or foyer and talk to people who will have just arrived or who’ve been perusing the exhibits.

If you’re only looking at spending 20 or 30 minutes with each participant you need make sure that you make the most of that time.

One issue I’ve had with cafe based research in the past is screening the participants properly. People often bend the truth to get cash incentives, so it’s important to spend the first 10-15 minutes of the interview asking them extensive screener questions. Are they really in your target user-base? This is pretty fundamental, especially if it’s a niche product.