Mechanisms are provided for modifying response of cognitive systems to user requests based on a determined knowledge level of the user and knowledge level of the concepts referenced in the cognitive system responses. The mechanisms receive a response to a user submitted request received from a client computing system and determine a first knowledge level of the user for a domain of the user submitted request. The mechanisms determine a second knowledge level associated with concepts referenced in the response and whether the first knowledge level is different from the second knowledge level. The mechanism, in response to the first knowledge level being different than the second knowledge level, modify content of the response to include concepts associated with the first knowledge level, to thereby generate a modified response. The modified response is then output to the client computing system associated with the user.