  Word clouds are a popular text visualization technique that summarize an
input text by displaying its most important words in a compact image. The
traditional layout methods do not take proximity effects between words into
account; this has been improved in semantic word clouds, where relative word
placement is controlled by edges in a word similarity graph. We introduce
MySemCloud, a new human-in-the-loop tool to visualize and edit semantic word
clouds. MySemCloud lets users perform computer-assisted local moves of words,
which improve or at least retain the semantic quality. To achieve this, we
construct a word similarity graph on which a system of forces is applied to
generate a compact initial layout with good semantic quality. The force system
also allows us to maintain these attributes after each user interaction, as
well as preserve the user's mental map. The tool provides algorithmic support
for the editing operations to help the user enhance the semantic quality of the
visualization, while adjusting it to their personal preference. We show that
MySemCloud provides high user satisfaction as well as permits users to create
layouts of higher quality than state-of-the-art semantic word cloud generation
tools.
