In general a course is very informative and useful. The issues were only some misconceptions, especially in formulas, between video examples and quiz questions.
Great idea for a specialization and bravo to the professor for capitalizing on her affiliation with a top-tier research university while working there as a visiting professor. Unfortunately the course is riddled with errors in the very first week which is problematic for at least two reasons: 1) it may be reinforcing learning that is factually inaccurate, and 2) it adds unnecessary time and frustration to the process.
I have taken several excellent courses from Coursera that are well-designed, and while most courses can be forgiven for having a few have small errors, this is the first time I have noticed multiple errors--and a few major obvious errors--immediately in one course. After hardly an hour of working with this course I canceled the subscription and am requesting a refund for the first month's payment. I hope the creators of this course clean up the errors and inconsistencies or take the course offline.