Automatic Creation of Evocative Witty Expressions

In linguistic creativity, the pragmatic effects of the message are often as important as its aesthetic properties. The productions of creative humans are often based both on a generic intent (such as amusing) and a specific one, for example to attract the attention of the audience, to provoke thoughts, to get the message home, to influence other people and change their attitudes and beliefs. In computational linguistic creativity, however, these pragmatic effects are rarely accounted for. Most works in automated linguistic creativity are limited to the production of a syntactically and semantically correct output that is also pleasing, but in applied scenarios it would be important to validate also the effectiveness of the output. This thesis aims at demonstrating that automatic systems can create productions that are attractive, pleasant and memorable, based on variations of well-known expressions, using the optimal innovation hypothesis as a frame of reference. In particular, these witty expressions can be used for evoking a given concept, improving its memorability, or for other pragmatic goals.