In order to review words effectively, all the information on a word should be kept in one place—in a notebook, for example, or on an index card. Index cards are convenient because the words can be placed in alphabetical order, which makes them easy to find when reviewing; and the cards can be carried around with you, so you can study them anywhere. You should try to be systematic about studying, so that you are sure to review each word at least once every couple of weeks.