[curiousjorge]

if I had some type of practical application that I knew could benefit from data science, like learning RoR to make a marketplace app for example, it would help a lot as I have a clear goal and route to achieve that. However, data science, machine learning, these are so broad, and seemingly complicated (my fear of complicated math formulas and statistics) and worse I don't know what I want to achieve out of it nor do I know what I want to make which really hinders the learning process for me. I need some incentive or reward at the end of the goal.

[sanderjd]

Yes, the step 1 that nobody seems to mention is that you need to have a question that you're curious about, which data analysis may be able to help you answer. The reward is having some answer to that question, with an argument for its validity. Instead of links to a bunch of datasets, I'd love to see a site that collects questions with the potential for data-driven answers. This perhaps exists somewhere.

[stickperson]

Absolutely. I remember seeing an "Epic NHL goal celebration" post on here a little while ago. That was a fun read and seemed like a good project to get some exposure to ML.

http://blog.francoismaillet.com/epic-celebration/