Creating and evaluating new product features is my world.
This book has a double grade:
If you know nothing about how to limit the scope of your product and validate it, this book is for you. It is a decent all-in-one plan to test a big idea in a week. The methodology is sound and fits in with decades of research regarding product development and design, as well as more recent work in usability and "lean" modes of development.
The book has judicious guidance on getting the right team together, getting focus, sketching, picking ideas to test, building a prototype, and, finally, testing with users and making decisions about the product idea. Yay! Awesome!
But.
If you know anything about product development and idea testing/validation, this is an incredibly annoying book. For those of you who know the field, I'd give this two or even just one stars.
Why? Just about every idea in this book is well known in product land. But the authors cite no works (except Jakob Nielsen, 'cos they wanted to use a graph from one of his publications), and there's no bibliography (they direct the reader to their web site, which is nice, but, folks, this is a book. And in a book you provide more resources through citations and a bibliography).
If you read this book naively, you would think that the great gods of Google Ventures somehow thought this up themselves.
There is a very big reason to belabor the long history of work in this area: It's because it's hard. Very hard.
Another thing to keep in mind with a book like this is that it's a guide for validating an idea in a week -- but by yourselves. I think it can be done. I think this book provides the map. But, trust me, having been through this many times, it can pay to have a facilitator who can sit in with your group and make this happen. These are people who are deep in this, have done it before, and know exactly where to bend the process to suit your group.
I have seen "regular people" try to test an idea, and it can go sideways very easily. To be sure, the authors know this. They know, for example, that CEOs can swamp an idea or justify the wrong one. Even with their smart words about keeping people in the room as much as possible, and giving the boss more votes at certain critical moments, there's a lot more to say about how hard it is to keep everyone honest. That frequently takes a third party who is disinterested.
Another thing that bugs me quite a bit about this book is the invocation of companies Google Ventures has invested in. Ooooh, Slack. Golly. Slack is cool and rich, so if they did this methodology, it must be the thing! Please, tell me about some failures.
I am sure I sound petty here, but these folks are sitting on the shoulders of giants. Among those giants: Jakob Nielsen, Donald Norman, Robert Cooper, Eric Ries, Nir Eyal, Marty Cagan, Steve Krug, agile software development (XP and Scrum), etc. Toss 'em a bone.