<i>For tech things I would say that just reading the documentation (or source if there isn&#x27;t any useful documentation) is preferable to any online courses.</i><p>I&#x27;m a big fan of the &quot;teach yourself by reading the docs&quot; thing and I&#x27;ve done a lot of that in my career.  But since I started doing a lot of these online courses, I&#x27;ve found that they can be very beneficial.   Having a little bit of structure around the learning process, having &quot;classmates&quot; to discuss with, etc. have helped me as I&#x27;ve been (for example) learning R.   Now, <i>could</i> I learn R by just reading books, tutorials, and experimenting on my own? Sure, of course.  But the courses are pretty cheap, add a little bit of rigor to the process, and come with a minor credential from a well known &#x2F; highly regarded university (Johns Hopkins, specifically).   All in all, I&#x27;ve found that this approach works really well.<p>Just to share an example of one regard in which the online classes have had value above and beyond me simply doing it entirely on my own...  The &quot;R ecosystem&quot; has a LOT of stuff in it.  If I just started playing around with R, I&#x27;d have little clue which libraries and other tools to try out.  But the courses I&#x27;ve done so far have guided me towards learning things like ggplot, dplyr, knitr, etc.  Knitr in particular turns out to be really cool, and I&#x27;m glad I discovered it... but I don&#x27;t think it&#x27;s something I would have gone looking for on my own.  Maybe I would still have found it eventually anyway, but as it stands, I feel like the course approach guided me in some useful directions early on.<p>YMMV, of course.