I am currently working towards the Johns Hopkins Data Science Specialization at Coursera. I am now complete with the first three courses. I posted my initial, and very positive, impressions when I was about half-way through the first four-week block. My impressions are still very favorable at completion. Now that the course is complete, I can post my complete thoughts for the first three courses.
There are a total of nine courses, and a capstone. After completing all 10 requirements you earn the “specialization”. After you complete a course you are given an “online certificate”. You can link this to your Linked In page, or other social media. You can see my first three certificates here.