On 07/23/2013 11:23 AM, Mathieu Stumpf wrote:
Here is what I would like to do : generating reports which give, for a given language, a list of words which are used on the web with a number evaluating its occurencies, but which are not in a given wiktionary.
How would you recommand to implemente that within the wikimedia infrastructure?
Some years back, I undertook to add entries for Swedish words in the English Wiktionary. You can follow my diary at http://en.wiktionary.org/wiki/User:LA2
Among the things I did was to extract a list of all Swedish words that already had entries. The best way was to use CatScan to list entries in categories for Swedish words. Even if there is a page called "men", this doesn't mean the Swedish word "men" has an entry, because it could be the English word "men" that is in that page.
Then I extracted all words from some known texts, e.g. novels, the Bible, government reports, and the Swedish Wikipedia, counting the number of occurrencies of each word. Case significance is a bit tricky. There should not be an entry for lower-case stockholm, so you can't just convert everything to lower case. But if a sentence begins with a capital letter, that word should not have a capitalized entry. Another tricky issue is abbreviations, which should keep the period, for example "i.e." rather than "i" and "e". But the period that ends a sentence should be removed. When splitting a text into words, I decided to keep all periods and initial capital letters, even if this leads to some false words.
When you have word frequency statistics for a text, and a list of existing entries from Wiktionary, you can compute the coverage, and I wrote a little script for this. I found that English Wiktionary already had Swedish entries covering 72% of the words in the Bible, and when I started to add entries for the most common of the missing words, I was able to increase this to 87% in just a single month (September 2010).
Many of the common words that were missing when I started were adverbs such as "thereof", "herein", which occur frequently in any text but are not very exciting to write entries about. This statistics-based approach gave me a reason to add those entries.
It is interesting to contrast a given text to a given dictionary in this way. The Swedish entries in the English Wiktionary is a different dictionary than the Swedish entries in the German or Danish Wiktionary. The kinds of words found in the Bible are different from those found in Wikipedia or in legal texts. There is not a single, universal text corpus that we can aim to cover. Google has released its ngram dataset. I'm not sure if it covers Swedish, but even if it does, it must differ from the corpus frequencies published by the Swedish Academy.
It is relatively easy to extract a list of existing entries from Wiktionary. But to prepare a given text corpus for frequency and coverage analysis needs more preparation.