  In this paper, we present Par4Sem, a semantic writing aid tool based on
adaptive paraphrasing. Unlike many annotation tools that are primarily used to
collect training examples, Par4Sem is integrated into a real word application,
in this case a writing aid tool, in order to collect training examples from
usage data. Par4Sem is a tool, which supports an adaptive, iterative, and
interactive process where the underlying machine learning models are updated
for each iteration using new training examples from usage data. After
motivating the use of ever-learning tools in NLP applications, we evaluate
Par4Sem by adopting it to a text simplification task through mere usage.
