  This work designs, evaluates, and improves a proposed search engine interface
for Visually Impaired VI users to efficiently perform web search activities.
Our conceptual modeling technique is based on Formal Concept Analysis FCA that
is used for data analysis. This approach highlights the hierarchized approach
to represent the discovered concepts. It is combined with context interactive
navigation in an interface which is called interactive search engine
(InteractSE). This interface aims to reduce the time and effort required by the
VI users to browse search results. InteractSE was evaluated by experts using
Nielsen heuristics and Web Content Accessibility Guidelines WCAG 2.0 for its
usability and accessibility. The analysis was carried out based on the
usability problems identified and their average severity ratings. The results
show that the most frequently violated heuristics from Nielsen set are
consistency, documentation, and the average severity rating of all the problems
is minor. The results also show that the most frequently violated WCAG 2
guidelines are distinguishable, followed by navigable and affordance. The
average severity rating of all the problems found using WCAG 2 guidelines is
also minor. The results show that Nielsen heuristics and WCAG 2.0 guidelines
contributed to identifying several usability problems, which might have missed
out if either of them was used alone.
