Q&A: what sources of information should people use to build products?

Here’s a question I was asked recently:

What sources of information do you suggest folks building their product plans today rely on, so that they can get the evidence they need to build the product that will meet the needs of end users?

Here’s my answer:

The answer is always: it depends – I know it’s the ultimate cop-out – but it depends on what you’re trying to demonstrate. The sources of data that you need to have will be dictated by what it is you’re trying to demonstrate or prove.

So let...