  User Stories record what must be built in projects that use agile practices.
User Stories serve both to estimate effort, generally measured in Story Points,
and to plan what should be done in a Sprint. Therefore, it is essential to
train software engineers on how to create simple, easily readable, and
comprehensive User Stories. For that reason, we designed, implemented, applied,
and evaluated a web application called User Story Tutor (UST). UST checks the
description of a given User Story for readability, and if needed, recommends
appropriate practices for improvement. UST also estimates a User Story effort
in Story Points using Machine Learning techniques. As such UST may support the
continuing education of agile development teams when writing and reviewing User
Stories. UST's ease of use was evaluated by 40 agile practitioners according to
the Technology Acceptance Model (TAM) and AttrakDiff. The TAM evaluation
averages were good in almost all considered variables. Application of the
AttrakDiff evaluation framework produced similar good results. Apparently, UST
can be used with good reliability. Applying UST to assist in the construction
of User Stories is a viable technique that, at the very least, can be used by
agile developments to complement and enhance current User Story creation.
