Welcome back everybody. What I want to do today is give you a quick introduction to the fourth course in this specialization, which focuses on how to evaluate user interfaces. Now let's situate this course in the context of the other courses in this specialization. In the first course we tried to get you to buy into user interface as this is important consideration to keep in mind. And went through a bunch of examples of good and bad design, and started to talk about how to find those examples. In the second course in this specialization, we showed you how to plan and conduct formative user research to analyze, makes sense of, and act on, the results. And, in particular, to idiate and select the best ideas and use those as the basis for your interface design. And in the third course, we actually went into how to do design. We spent a bunch of time on low fidelity prototyping methods, design principles and patterns that you can apply across designs, universal design, how to design for different types of populations, and then on how to design in different platforms and contexts. So if you've gone through those previous courses, that's just a quick reminder. If not, that is the grounds that we have covered that sort of sets up this course. And in this course, what we're going to focus on are questions like, okay now that I've created something, does it work or what's wrong with it and how to improve that. Now, when we think about evaluating user interfaces, evaluation is part of an iterative design process. Where you're going to cycle through steps of understanding user problems, doing research, doing design, evaluating and then returning to understand more about users redesign and so on as necessary. So, what we're going to focus on in this course is methods to evaluate user interfaces, structured systematic methods to evaluate user interfaces, both without users and with users. And you'll see how you can do this using different types of tools in different settings, ranging from fairly formal laboratory settings where you might use things like eye trackers. To informal settings where you are simply observing as people use an interface and gather from that. Do they understand the concept, are there significant problems they're running into and so on. And in this course we'll have several quizzes as well as three assignments. In two of those assignments you will be evaluating the user interface using methods that let you do so without users. And in the third assignment you will be developing a plan for testing the user interface with users. By the end of this course, you will be able to apply a number of methods for testing a user interface without users. You will be able to develop an actionable and effective plan for testing a user interface with users, and you will be able to identify and apply a range of methods for testing a user interface with users. Well that's it for this brief overview of the course and in the next video, I'm actually going to step through much more of the details of how you go about evaluating interfaces, how it fits into the process and give you a little flavor of what we will be doing in this course.