  An eye-tracking study of 18 developers reading and summarizing Java methods
is presented. The developers provide a written summary for methods assigned to
them. In total, 63 methods are used from five different systems. Previous
studies on this topic use only short methods presented in isolation usually as
images. In contrast, this work presents the study in the Eclipse IDE allowing
access to all the source code in the system. The developer can navigate via
scrolling and switching files while writing the summary. New eye-tracking
infrastructure allows for this improvement in the study environment. Data
collected includes eye gazes on source code, written summaries, and time to
complete each summary. Unlike prior work that concluded developers focus on the
signature the most, these results indicate that they tend to focus on the
method body more than the signature. Moreover, both experts and novices tend to
revisit control flow terms rather than reading them for a long period. They
also spend a significant amount of gaze time and have higher gaze visits when
they read call terms. Experts tend to revisit the body of the method
significantly more frequently than its signature as the size of the method
increases. Moreover, experts tend to write their summaries from source code
lines that they read the most.
