Commonplace books (or commonplaces) are a way to compile knowledge, usually by writing information into books. Such books are essentially scrapbooks filled with items of every kind: recipes, quotes, letters, poems, tables of weights and measures, proverbs, prayers, legal formulas. Commonplaces are used by readers, writers, students, and scholars as an aid for remembering useful concepts or facts they have learned. Each commonplace book is unique to its creator’s particular interests. They became significant in Early Modern Europe.
It is interesting that the maintaining of a commonplace book was encouraged as part of your academic study. Lab notebooks have certainly retained their place in the more sciencey parts of academia but I’m not sure commonplace books have.
The wiki entry did suggest that blogs have common thread with commonplace books — I like that line of thinking. You could look at a blog like Brett Terpstra’s as a “commonplace” blog for his discovery of code snippets and their repurposing for his own endeavors. You could also look at the resurgence of personal journaling (Day One is my personal tool of choice here) enabling the same behavior.