Very basic well-formedness test for english.

gistfile1.rb

documents = Document.all(:limit=>10) # get some documents

# use map to iterate over the documents & return the percentage
# of the document's words that are in the spell check dictionary
results = documents.map do |doc|
  checked = Spellchecker.check(doc.combined_page_text) # check the text
  correct = checked.select{ |entry| entry[:correct] }  # get the correct words
  percentage = correct.size.to_f / checked.size        # find the percentage
  puts "#{doc.id}: #{percentage} (#{correct.size} of #{checked.size})" # print out some status info.
  [doc.id, {:percent => percentage, :correct => correct.size, :checked => checked.size}] # return the document's id, and it's percentage
end

percentages = Hash[results]