I was in grade school during the 1970's. I remember being given the direct learning for English grammar in the 5th grade. The intent was that all grammar topics from sentance structure to punctuation, verbs nouns, etc... were broken down into indevidual "laerning modules". The teacher gave a brief lesson then the student were allowed to take the module and do the learning assignments. The intent was that student would progress at their own pace. I can tell you that at the age of 10 I couldn't care lass about learning grammer. I was allowed to simply not move on. There was no push to get me through all the material and as a a result I never did learn proper grammar or sentance structure.
In our technical school we use some limited "on-line" self directed study. It has been my personal observation that this new generation is no more self motivated now then I was then. If it looks like work or if it's something they "need" to learn they are just as likely not to do it no matter how convenient you make it.