Barrier is related to Wall. Wall is a type of Fence. Fence is related to Field. 
Character is a type of Trait. Character is a synonym of Sort. Sort is a synonym of Class. you are likely to find Confusion in/at/on Class. 
Barrier <--RelatedTo--> Wall --IsA--> Fence <--RelatedTo--> Field 
Trait <--IsA-- Character <--Synonym--> Sort <--Synonym--> Class <--AtLocation-- Confusion 