On 12/10/2010 Google announced they have added a reading level advanced search feature to Google organic search. While I don’t see this as a huge ranking opportunity for ecommerce shops, I do think that Google will adapt some sort of automation for regular organic results… Should they be happy with the operation and results of the advanced search feature. Having said that, it’s a good thing for usability and the potential for future rank to make sure that your webpages are at a digestible level of reading for your shopper base. Let’s face it, shoppers rarely buy what they cannot understand.

Search results at every reading level
We work every day to make information available to everyone on the web. This week we made it easier for to you pinpoint exactly the information you need with a new advanced search feature that categorizes results by reading level. For example, if you’re writing a college paper on [herbivores] you can refine to see only advanced material, or if you’re a grade school teacher preparing for a class on [herbivores] you can refine to see only basic material. To try it out, click “advanced search” to the right of the search box and click in the new reading level section. You can filter to see only results that are basic, intermediate or advanced, and annotate results with reading levels. If you choose to annotate results, on the results page you’ll see a graphical distribution of the pages classified in different categories for your search.

Very certainly this isn’t any deal breaker, but I suspect some of the more technical shops might be putting out information that is, well, over their shopper’s heads. As far as readability, there are 2 popular and accepted standards: Gunning-Fog Index and Flesch–Kincaid Readability Test. These scales are similar, but not the same. It would be expected that Google is using one of these, a combination or derivative of these for it’s readability advanced search filtering.

Flesch–Kincaid Readability Test

Algorithm used to determine the Flesch–Kincaid Readability Test score

  1. Calculate the average number of words per sentence.
  2. Calculate the average number of syllables per word.
  3. Multiply the average number of syllables per word multiplied by 84.6 and subtract it from the average number of words multiplied by 1.015.
  4. Subtract the result from 206.835.

Algorithm: 206.835 – (1.015 * average_words_sentence) – (84.6 * average_syllables_word) – Wiki Info

Flesch–Kincaid Readability Test Score

90.0–100.0 easily understandable by an average 11-year-old student
60.0–70.0 easily understandable by 13- to 15-year-old students
0.0–30.0 best understood by university graduates

Gunning-Fog Index

Algorithm to determine the Gunning-Fog index score

  1. Calculate the average number of words per sentence.
  2. Calculate the percentage of difficult wo