Recruiting is hard. It's just finding the needles in the haystack. You can't know enough in a one-hour interview. So, in the end, it's ultimately based on your gut. How do I feel about this person? What are they like when they're challenged? I ask everybody that: 'Why are you here?' The answers themselves are not what you're looking for. It's the meta-data.
Motivating Thoughts of Steve Jobs (ed. Prabhat Prakashan) - ISBN: 9789351869191