Limits of Vocabularies

The latest assessment by observation on information research demonstrated that the most difficult part is the limitation of using vast of vocabulary.
For example, the Student X could not communicate "crime by different social classes" as crime by blue and white collar, crime by poor and rich, crime by gender, crime in different age categories, crime within groups of different status of education, etc.
The social aspect content was not explain how to identify, construct, and maintain vocally description of the research information.
The focus on transactions of keyword searching, compound terms, and Boolean operations was absent.