This document analyzes the topics discussed in issue reports for Firefox from 2005-2010 and Chrome from 2008-2010. The researchers identified topics using latent Dirichlet allocation and found Firefox issues covered a heterogeneous range of topics, while Chrome topics focused more on performance and multimedia. Some common overlapping topics between the browsers included page layout, multimedia issues like video players, and user interface topics. The overlap was highest in later periods and for more generic topics.

1. What Topics do Firefox and
Chrome Contributors Discuss?
Mario Luca Bernardi, Carmine Sementa
Quirino Zagarese, Damiano Distante
Massimiliano Di Penta
dipenta@unisannio.it

2. Context
 Nowadays Web browsers are among
the most widely used applications
Firefox and Chrome the 2nd and 3rd
top popular browsers
 They evolve to fix bugs, introduce new
features, cope with market and the
evolution of the Web
 (part of) their evolution tracked by Bug
Tracking Systems

3. What we do
 Goal: analyze the topics discussed in issue
reports over time
 Context:
 88,538 Firefox issues (2005-2010)
 49,986 Chrome issue reports (2008-2010)
 Research Questions:
 RQ1: topics discussed over time
 RQ2: overlap between Firefox and Chrome
topics
 RQ3: overlap in the same time frame

4. Analysis process
 Term extraction and indexing
 Extraction of text from HTML pages
 Stop words removal, stemming, tf indexing
 Topic mining
 Group bugs into semester periods
 Topic identification using
Latent Dirichlet Allocation (LDA)
 Issue classification into topics
 Topic co-evolution analysis
 Topics to which most issues pertain
 (Jaccard) overlap between popular topics
discussed for the two browsers

5. Most popular topics: Firefox
2005 S1 width; px; border; height; align Layouting/
2005 S2 width; background; px; height; border formatting
issues
2006 S1 px; width; border; cell; posit
2006 S2 enabl; disabl; usr; warn; gmake Low-level
2007 S1 home; match; bin; zbyszek; crt and building
issues
2007 S2 ctype; lc; match; moz; nsiframe
2008 S1 leak; zoom; extension; addon; total Layouting/
2008 S2 width; px; background; border; size formatting
issues
2009 S1 ircategoryopt; home; warn; unexpected; tinderbox
2009 S2 elem; width; height; px; tag
2010 S1 slave; reftest; unexpected; mochitest; pass

6. Most popular topics: Chrome
2008 S2 slave; messageloop; offici; signatur; pump Low-level /
2009 S1 pump; messagepumpwin; wchar; dispatch; ntdll performance
2009 S2 player; quicktim; mb; ram; ghz; hostnam Multimedia /
2010 S1 info; player; quicktim; mb; signatur performance

7. Overlapping topics

8. Overlapping (same period)
Period Overlapping topic
2008 S2 movi; youtub; stop; video; player; game; plai; flash; sound
2008 S2 left; width; height; border; px
2008 S2 cpu; task; usag; slow; hang
2008 S2 hit; shift; tag; keyboard; focu
2008 S2 usernam; account; login; email; authent
2009 S1 youtub; video; player; plai; flash
2009 S1 width; background; bottom; size; posit
2009 S2 left; mous; bottom; posit; screen
2010 S1 left; width; resiz; bottom; height; size; border; posit; px
2010 S1 restart; visit; login; comput; websit; hang

9. Conclusions
 Discussion about:
 Firefox: quite heterogeneous
 Chrome: mainly related to performance
and multimedia
 Non negligible overlap
 Related to generic topics
– e.g., page layouting
 Related to multimedia in recent periods

10. Thank you!
Questions?

11. Overlapping topics
Firefox Chrome Common terms in the topics
2008 S2 2008 S2 movi; youtub; stop; video; player; game; plai; flash; sound
2009 S1 2008 S2 youtub; stop; video; player; watch; game; plai; flash; sound
2010 S1 2010 S1 left; width; resiz; bottom; height; size; border; posit; px
2005 S2 2008 S2 movi; stop; video; shockwav; player; game; plai; flash
2006 S1 2009 S2 mous; resiz; ctrl; size; posit; screen; keyboard; focu
2006 S2 2009 S1 width; resiz; background; bottom; size; visibl; posit; scrollbar
2007 S2 2008 S2 youtub; movi; video; player; watch; plai; sound; flash
2007 S2 2010 S1 width; resiz; bottom; height; border; size; posit; px
2007 S2 2010 S1 mous; hit; ctrl; reload; shift; activ; focu; keyboard
2008 S1 2010 S1 width; resiz; bottom; height; size; border; posit; px
2009 S1 2010 S1 youtub; stop; video; player; watch; plai; ogg; sound
2009 S1 2010 S1 width; left; bottom; height; size; border; posit; px
2010 S1 2008 S2 left; width; resiz; bottom; height; border; px; pixel