Can I post study notes based on a book to my personal website?

Question

When taking a course I deemed specially important as an undergrad, I would usually choose a book from the bibliography the professor provided and read it independently of the classes; while reading, I would write study notes in LaTeX based on the book.

Now, they would follow the book sometimes quite closely, but most of the times they included many modifications: boring (according to me) sections would be skipped, omitted or incomplete proofs were appropriately completed, notations I found confusing were changed, some topics from other books would be added and, most importantly, while all books to which I chose to apply this process were in english, my notes were always written in my first language.

Many years later, I found these study notes and would like to add them to my personal website.

My question is: can I add these notes to my website?

I am citing the books which inspired the notes (and even the books I read on the same subject but were not incorporated into the notes), explicitly mentioning they were not only references but were somewhat "copied" to produce the notes.

But can I be accused of plagiarizing the sources, given the similitude between my notes and the books?

Would I be violating copyrights (I know there are many copyright types, but in general)?

I don't intend to have any monetary gain from these notes, but would like to make them available to whoever finds them interesting, together with their source codes in case anyone wishes to modify them.

Answer 1

If you cite what you use then you are safe against charges of plagiarism. Citation is an absolute guard here.

In general you can do what you like with your own words and thoughts.

That leaves only the question of copyright, which varies around the world. I'll speak generally about the requirements, though your country may treat things differently:

Copyright law is civil, not criminal law. You can be sued, but not arrested for violations. Copyright law has some exceptions for academic and other purposes, but they tend to become more limited over time.

In general, the underlying idea is that you shouldn't reduce the value of a copyrighted work in writing "about" it. This often comes down to quoting (copying) large sections where "large" is actually quite small. Even paraphrasing large sections can cause you trouble. So, providing an alternate edition of a copyrighted work will probably be a serious violation (if it is discovered) even if you don't literally copy anything. Copying too many "short" sections is also suspect.

The copyright lawyers employed in some industries are very (very) vigilant.

However, some things that appear in textbooks (especially undergraduate textbooks) are actually common knowledge. Most Calculus books or Java Programming books tend to look a lot alike, differing primarily in the exercises. In fact, for many of them, the exercises are more important to learning than the text itself. So, if you put together a lot of ideas that you learned from a Calculus text and followed the general flow of topics, it would be difficult to accuse you of a violation unless you literally copy too many of the words.

While publishing solutions to exercises is less likely to be a formal or legal violation, you can make a book generally useless for learning if you make it easy for students to avoid thinking and just copy what you have done. Reading a solution is a completely different mental process than producing one. So, it is possible to interfere in the development of a student by providing solutions. I think that is an ethical issue, though others will disagree.

The difficulty, though, is that the whole question isn't cut and dried and is open to interpretation in a law suit if one arises. Lawsuits can be very expensive to defend against, so it is wise to be cautious.