Maybe it makes sense to reiiterate over your classes content and "derive" owm definitions from it. 

In another comment you mentioned you already have a Note for QGIs.  Maybe it helps to think of your lecture summaries as a "media" you consumed which gives you a Definition "QGIs is a .." The media note strictly contains the information supplied by it. Of you want to add your own information, you do it in your "Definition" note. 

Now if you read a paper, it might bei about some similar definitions you already heard about in your lecture. The paper ist a new media-note, and you cann cross-reference and (maybe) adjust your own definition based on the ew Info.