1. What Makes a Good Code Example?
A Study of Programming Q&A in StackOverflow
Sayed Mehdi
Nasehi,Jonathan Sillito,
Frank Maurer, Chris Burns
Presented By: Mohammad Masudur Rahman

2. Contents
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Why Code Example?
Thesis Statement
Stackoverflow Overview
Scores, Answer Types & Question Types
Attributes of Recognized/Good Answer
Attributes of Low-vote Answer
Important Findings & Suggestions
Limitations & Future Works

3. Why Code Example?
 New
technology, language, API & tools
 Learning psychology – working sample
teaches much
 Developer’s productivity
 What is a good code example? –open
question

4. Thesis Statement
A
good code example should include
comprehensive code as well as the text
explaining the code
 Programming Q&A site like Stackoverflow
provides more customized and helpful
answer to question rather than existing API
documentation, code repositories or search
engines

5. StackOverflow (http://stackoverflow.com/)
A
Programming Q&A site 1m users, 2.78m
questions, 5.77m answers and 10.5m
comments (up to March, 2012)
 Natural language search engine
 Question, tags, badges
 Answer, Editing, Comments
 Up vote, Down vote, Reputation
 89 sites: http://stackexchange.com/sites#

6. Scores
A
metric for Good and bad example
 Score = (Up vote – Down Vote)
 Normalized Score
 87% got <3, 13% got 10
 High score threshold 4

7. Answer Types
 Good
= Recognized
 Accepted = Recognized
 Unaccepted but score >=.4, then recognized
 Low vote (score <=.1)
 Long answer

8. Question Types
 Classification
criteria – tag/topic & what to
be solved
 Debug /Corrective
 Need-to-know
 How-to-do-it
 Seeking-different-solution

9. Attributes of a Recognized Answer
 Concise
code
 Using question context
 Highlighting important elements
 Step by step solutions
 Providing links to external resources
 Inline documentation

10. Attributes of Low Vote Answer
 Lack
of code
 Lack of explanation
 Shortcomings of solution

11. Answer Recognized but without Code
 Code
may not be necessary
 Link to external resources
 API Queries

12. Important Suggestions
 Can
the mining tools provide customized
example from code repos. based on
questioner’s expertise? –No, so make it
intelligent
 Plaintext documentation- same for all, not
helpful, so, make it wiki-like to meet user’s
needs.

13. Important Findings
 Customized
Answer: suits to questioner
needs better than API Docs, code
repositories or search engines.
 Customized Answer: reduces mental effort to
understand things, reduces cognitive
distance with info source
 Familiar context in solution
 Impact of question types on answer

14. My Observation
 Only
considered Java related Q &A
 Threshold could be changed over time,
Cohen’s kappa measurement
 Only score as a metric which may not be
feasible
 Posting time, responder’s identity, question
topic may affect the scores

15. Future Works
 Using
to characteristics of good code
example to we can suggest developer at
coding time with IDE
 Evaluate open-source code quality

16. Thank you
Questions?