Mendeley is a bibliography app that has a social network revolving around publications. I use it mainly for maintaining a library with the pdf version of the all the useful papers I have come across, and it stores all its publication information too.
Evernote is an app with the slogan 'remember everything'. It manages and stores notes, which can include html formatted text, pdf files, and images, as well as have attached any file(!). Evernote can also take audio, screenshots, webcam notes, as well as handwritten notes taken using a tablet. The first three can hold all the features I described, while the handwritten notes cannot.
The thing about these two is that they store a huge amount of entries and have the power to let me find what I am looking for. But let me be more specific:
- They can search within the pdf documents and within notes. In Mendeley, you can add notes, highlight text, and add notes to the highlighted text. In Evernote, you can add pdfs to your notes.
- They manage, store, and index meta-data. To me, meta-data is comprised of tags, folder structure, and added characteristics of an object (like the title, authors, year of publication of an article in pdf.) Right now, as I am writing this in my desktop Evernote console, I have tagged this note as 'blog' and 'blog idea'. It will pop up when I subset using the tags, and I can include these tags in my search. In Mendeley, I can subset using the tags that accompany the required readings for the causal inference class for which I am a teaching assistant, and since I made a tag for each lecture topic, it is quite easy for me to find those articles. Also, tags allow for tracking objects that can be in two different categories at the same time, folders do not allow for this (thanks to Gmail and Google docs for explaining this to me.) My favorite use of notes on highlighted text in Mendeley is to mark statements that are directly applicable to my research, like 'this theorem can be used in _____ paper'. Consistency in the usage of tags is crucial when searching.
- Automatic meta-data. Mendeley extracts meta-data from the pdfs AND compliments it by web search in Google Scholar. A well-groomed library, for me, is one that has all the information from the articles and book chapters, webpages and working papers, and with Mendeley, most of the job is done automatically. When it is groomed, it is much easier to get the correct bibliography from Mendeley. It can automatically create bibtex files of your library and has an app to build bibliography in Microsoft Word. As for Evernote, there is a webclipper app that, when you clip, it automatically sets the folder and tags that match the content of the clipped webpage (and you can remove them if they are not appropriate.) Yeah, Evernote learns what you do.
- They are backed up on the cloud. Also, they are integrated with iOS and Android. Mendeley is developing their Android application, but there are other already-developed apps that use Mendeley's online storage of my library. The quality of the integration between Android Evernote and Desktop Evernote comes down to how fast it can sync between the two of them (if you update notes simultaneously on the desktop and in your phone, it now shows conflicting notes and keeps both versions).
Post a comment if you know of another program that works great with meta-data, specially if it is one about file structure in the drive. I would love it if Dropbox/Cubby/Copy had something like this too. As far as I can tell, Google Drive cannot handle meta-data, although it doesn't seem to need it that much given its search capabilities.