The editors of dictionaries will spend a few hours a day reading newspapers, magazines, online publications, different published material, published books and anything published electronically. They will find words that aren't in the dictionary and determine if they would work or not. But before doing this they must determine the meaning or the usage of the word. The editors mark all words of interest along with the word's context and outlining text.
If the word seems of interest and might be a possibility to add to a dictionary they are entered into a computer and stored in a machine-readable form. Furthermore, they will create a 3 x 5 card that is also stored on the computer. On the card is the word, the context, surrounding text, and how the word was used in a sentence.
Now it is up to the editors to review each of the citations and determine if this will be added to the dictionary or not. Normally the editors will only review a small segment of the letters at a time to make it easier to review the words and what words are already published in the dictionary. The meaning of the word and the context in how it was used will play an import role in determining if this word is added to the dictionary or not.