Update tdd-1-unguided.md

tdd-1-unguided.md

@@ -4,6 +4,6 @@ In this task, you'll design and implement a simple autocomplete feature.
 
 [Autocomplete starter code] (code here)
 
-Whenever the user begins typing a new word, your autocomplete will recommend possible completions based on the words that the user has already entered in the text area.
+Whenever the user begins typing a new word, your autocomplete will recommend possible completions. Your autocomplete will generate completions based on the words that the user has already entered in the text area, ranking valid possible completions from most to least likely based on the frequency of the word in existing text. If there are no possible completions based on these words, your system should generate an empty list of completions.
 
 **Design and implement the autocomplete feature.** Your goal is to build a working implementation and to craft a clear and easy to maintain design. You have up to 15 minutes. Notify the experimenter when you're done.