Vocabulary Profiling

I think the fail of guessing a word is depend on the level of the student and the level of the use of language because if  the content covers high level of English it is more often to fail to guess the word .In addition, if the student is engage with the 90 % of the other  words then it is more easy for him to success. I believe that it happens to all of us because we do not have the ability to know the all words of English , so it  sometimes happens to me as well .