2017-06-24: 有提到survey回复率较低，一般多少的文章：
During the study period, we sent 465 emails and received
195 responses, achieving a response rate of 41.9%. Each
response corresponds to a distinct developer and commit.
The achieved response rate is significantly larger than the
typical 5% rate found in questionnaire-based software engineering
surveys [32].
文章名：Why We Refactor? Confessions of GitHub Contributors
对很标准的表达地点，系统应该识别很高，
不准确表达（省略，拼写错误啥的）比例会很高么？对各种不准确的一个演化过程，
informal text->inexact search：如何保证准确度的，拼写错误啥的。
all possible positions:如何控制量，认为来做么？
假设是很宏观的同一个名字，用什么方法来定位到具体的地点呢？这个有考虑么？
假设不存在搜不到的，怎么处理？
做问卷调查的一个貌似还不错的工具
http://app.surveygizmo.com
