Sentence:  We speculate that <WSD>compulsives</WSD> in the unstructured schools are under greater strain because of the lack of systemization in their school setting , but that their need to organize ( for comfort ) is so intense that they struggle to induce the phonic rules and achieve in spite of the lack of direction from the environment . 
Meaning of the word marked with <WSD> tags:  a person with a compulsive disposition; someone who feels compelled to do certain things