It can easily be imagined that this effect can be subtle. For example, similar languages will have a higher coincidence count than dissimilar languages. Also, it isn't hard to generate random text with a frequency distribution similar to real text, artificially raising the coincidence count. Nevertheless, this technique can be used effectively to identify when two texts are likely to contain meaningful information in the same language using the same alphabet, to discover periods for repeating keys, and to uncover many other kinds of nonrandom phenomena within or among ciphertexts.