Techniques for machine learning analysis are provided. A machine learning (ML) model is trained to identify appropriate documents based on lexical knowledge of target groups. A lexical knowledge of a set of users is determined. Additionally, a first document of a plurality of documents is selected by processing the determined level of lexical knowledge using the ML model. The first document is presented to the set of users. A level of engagement of the set of users is then determined. Upon determining that the level of engagement is below a predefined threshold, a second document of the plurality of documents is selected using the ML model.