If you've hunted high and low for a document only to find it at some other time in a perfectly logical place, you could benefit from a cross-reference system. As a student with many projects and research projects in your future, a simple, straightforward cross-referencing system can help keep you organized with an efficient process.
A cross-reference system is a method in which you file a document or a note about the location of the document under multiple categories. Such a system is particularly helpful when it's not clear-cut where a specific document truly belongs. For example, you could file a research study about teenagers and cell phone usage under “teens” and “cell phones.” Or you could file the study under “teens” and insert a note under “cell phones” that says, “See study about teens and cell phones, filed under 'teens.'” It might take you a few additional minutes to create an extra record so that you keep your cross-reference system up-to-date and organized, but your investment will be well worth the time you spent.
A cross-reference system will serve you well as a student and in other pursuits, as well. If you're learning to cook, you could file recipes under multiple categories. For example, you might file a lasagne recipe under “Italian dinners” and “pasta.” The beauty of a cross-reference system is that you can and should tailor it to your needs and thinking style. If you're especially protective about a vegetarian lasagne recipe, you might even add a third category: “meatless dishes.”