Presage is an intelligent predictive text entry system.

Presage (formerly known as Soothsayer) generates predictions by modelling natural language as a combination of redundant information sources. Presage computes probabilities for words which are most likely to be entered next by merging predictions generated by the different predictive algorithms. Presage’s modular and extensible architecture allows its language model to be extended and customized to utilize statistical, syntactic, and semantic predictive algorithms.

A predictive text entry system attempts to improve the ease and speed of textual input by predicting words. Word prediction consists in computing which word tokens or word completions are most likely to be entered next. The system analyses the text already entered and combines the information thus extracted with other information sources to calculate the set of most probable tokens.

A typical presage-based application would display the set of most probable tokens (i.e. a list of suggestions) to the user and automatically enter the desired token after the user selects it. If the list of suggestions does not contain the desired word, the user continues entering text until the correct suggestion is offered or until the user is done entering text.

Presage is fundamentally different from predictive input technologies commonly found on mobile phones, which might more accurately be described as ‘disambiguating text entry’ rather than ‘predictive text entry’ systems.

Such systems do not try to guess what the user intends to write in the future, only to determine what they most-likely intend to write in the present, given their past input.

Presage, on the other hand, actively predicts the what the user intends to write, and only reverts to word completion mode if the prediction did not contain the desired token.

Presage is free software. It is distributed under the term of the General Public License.