I missed the first half of the lecture, so this section I will cover later when the slides are released
The ultimate tiebreaker when it comes to usability is, it shouldn’t make you think, you shouldn’t think about using it, you’re just navigating it.
Choice of words is important when designing a site, it is better to use simpler terms to explain something or to showcase a function. It’s not dumbing down, it’s opening up
that being said often typography can be often laid out poorly:

Go for the typography that is most important for the user, Don’t force them to work your way to read it, work theirs
Usability Test is when one user at a time is shown something whether thats a website or sketches, and they are asked to figure out what it is or try to get them to do a task, if you want a great product, you have to test. testing one user is better than none, testing one user early in the project is better than testing 50 near the end.
The importance of recruiting representative users is overrated, if your making an app for children, and you don’t know any, try testing with a teenager, or a mum! the point of testing is not to prove or disprove something, it’s to ensure its to work.
Testing is an iterative process
How many users should you test with? Nielson say that 5 users find 80% of issues in a product, take anyone you can get within limits
There are exceptions when it comes to usability testing