Here's a review I just posted on CourseTalk.com (a review site for online courses, including MOOCs) of "Introduction to Mathematical Thinking," which runs on Coursera: IN A NUTSHELL: This MOOC has excellent content, but the Coursera platform and absence of an instructor undermine it. DETAILS: I was able to complete 7 fairly enjoyable weeks out of the scheduled 10 weeks of this course before health reasons forced me to opt out of weeks 8, 9, and 10. Nonetheless I still feel I should warn persons interested in this topic to be careful about selecting this course in future. 1) Although the blurb for the course says it's meant not just for math majors, but for anyone interested in logic, strictly speaking this isn't true - the focus is entirely on mathematical logic & proofs. 2) You'll want a good background in high school algebra, especially factoring, to do well in the final weeks. 3) The instructor, Keith Devlin, has said he will no longer be involved; this spells trouble for getting good mentors, who are sorely needed. 4) The revised Coursera platform is awful, esp. the changes to the forum - even the mentors said so. 5) Another problem with Coursera is that people can race ahead as they please; this reduces forum participation even further. Conclusion: lecture content is good, but platform & forum participation are poor. Here is the link to the Coursetalk page for this course; and here is the link to the corresponding Coursera page. To expand on my mini-review, the instructor (Devlin) took great pains in creating the original version of this MOOC on Coursera several years ago; and those who completed it (including some of the current mentors when I took it) really loved it. I almost loved it - the lecture presentations are really quite good, and the assignments and quizzes very well thought-out - but felt that management of the course became increasingly hamstrung as each week went by. Devlin has posted on one of his blogs that he was disappointed in the changes about a year ago to the Coursera platform; and at least one mentor who I worked with agrees. Previously, you couldn't access upcoming weeks of content until the current week was completed; this kept everyone in lock-step and made sure that forums would always have people working on the same content. No longer - now the fast learners can race ahead, which they may prefer; but it makes it harder for the mentors since they can't concentrate on a single week, and harder for the other students who want help in the forums from people working on the same content as they are. Aside from that, there were apparently some other changes to the platform that also made it less effective, but I'm not familiar with what those are. Devlin participated in the first couple of weeks of the forums to a small degree; but then totally withdrew. Having taught, I know what it's like to burn out on a course you put your heart into for many years; and my impression is, he has just plain lost interest & lost faith in the Coursera offering as it now stands. I think the course will suffer without him directing it & was already showing signs of this; for example, of the dozen or so mentors, all seemed to drop out after the first few weeks but three. The three who stayed on were very helpful; but without an instructor, I wonder how Coursera will recruit mentors going forward & who is going to motivate these mentors? Perhaps they can find a very motivated "super mentor"? The experience has left me much less likely to take an online course in the future, unless it's a course where I know an actual instructor will be participating. Videos aren't enough for effective, enjoyable instruction; you need mentors & classmates at a minimum; and mentors surely want someone to guide them & give them some strokes for doing a good job. That calls for an instructor.