Before we dive into each of the individual hypothesis areas, I thought we might loop through a few overviews. I think this will be useful for you for two reasons. One, all of these hypotheses rely on each other, reference each other, build on each other, and it's useful for you to start thinking about those interrelationships. Number two, I think it's good for you to start thinking about how these apply to your work, and asking yourself those questions, and also asking yourself, where might you apply some of these ideas to get some initial practice. With that said, let's have a look at the persona hypothesis. For each of these areas, we're going to look at these four questions. Let's dive into this and do a quick overview for the persona hypothesis. What is a persona? It is a humanized, but specific view of who your user is, and what makes them tick. So for example, with HVAC in a Hurry, we have Trent, the technician. He goes out and he fixes HVACs. We know that any given person on the street or the works at HVAC in a Hurry is one of these people. If we asked them, how many HVACs did you repair last week? We get the answer that it's more than five. Less than that, they might be a facilities manager or a handyman for example, something like that. So you may ask, and I get the question all the time, why is it important to be so specific? Why not just swing for the fences and build something for everybody? The reality is, that just doesn't work. In this hyper competitive, hyper noisy world that your digital solutions is going to go out into, you need something that's not just not wrong, but also testably right or wrong, [inaudible] right or wrong for a particular type of user. Ultimately, your product may have lots of different users and lots of different segments, but you're going to win those one by one. How do you know if you need this? Well, all the other work we're going to do builds on the idea that you have a persona or personas in mind. Without it, your results won't converge. It'll be hard to make good decisions. You'll spend a lot of time hedging and second guessing, and that isn't compatible with the practice of hypothesis-driven development or a healthy practice of Agile and good focus product delivery. How do you go out and ask and answer these questions? Well, the good news is, it's pretty easy. You create an interview guide. You can go out and answer the questions about both your persona and your problem hypothesis in one week or less. It doesn't have to be a big deal. It's something you can do continuously. Then how do you use these results? Well, a healthy, durable persona or set of personas is going to be a constant part of your conversations about what you're designing, what you're building, how you're supporting it, and how you're promoting it. Ultimately, we will have examples in the week where we go into these in more detail. But ultimately, these are extremely practical assets that will be a really important durable part of your practice of hypothesis driven development.