04_getting-help_help.pdf
- 1. GettingHelp GettingHelp Roger D. Peng, Associate Professor of Biostatistics Johns Hopkins Bloomberg School of Public Health
- 2. Asking Questions Asking Questions Asking questions via email is different from asking questions in person People on the other side do not have the background information you have Other people are busy; their time is limited The instructor (me) is here to help in all circumstances but may not be able to answer all questions! · · they also don’t know you personally (usually) - · · 2/14
- 3. Finding Answers Finding Answers Try to find an answer by searching the archives of the forum you plan to post to. Try to find an answer by searching the Web. Try to find an answer by reading the manual. Try to find an answer by reading a FAQ. Try to find an answer by inspection or experimentation. Try to find an answer by asking a skilled friend. If you're a programmer, try to find an answer by reading the source code. · · · · · · · 3/14
- 4. Asking Questions Asking Questions It’s important to let other people know that you’ve done all of the previous things already If the answer is in the documentation, the answer will be “Read the documentation” · · one email round wasted - 4/14
- 5. Example: Error Messages Example: Error Messages > library(datasets) > data(airquality) > cor(airquality) Error in cor(airquality) : missing observations in cov/cor 5/14
- 6. Google is your friend Google is your friend 6/14
- 7. Asking Questions Asking Questions What steps will reproduce the problem? What is the expected output? What do you see instead? What version of the product (e.g. R, packages, etc.) are you using? What operating system? Additional information · · · · · · 7/14
- 8. Subject Headers Subject Headers Stupid: "Help! Can't fit linear model!" Smart: "R 3.0.2 lm() function produces seg fault with large data frame, Mac OS X 10.9.1" Smarter: "R 3.0.2 lm() function on Mac OS X 10.9.1 -- seg fault on large data frame" · · · 8/14
- 9. Do Do Describe the goal, not the step Be explicit about your question Do provide the minimum amount of information necessary (volume is not precision) Be courteous (it never hurts) Follow up with the solution (if found) · · · · · 9/14
- 10. Don't Don't Claim that you’ve found a bug Grovel as a substitute for doing your homework Post homework questions on mailing lists (we’ve seen them all) Email multiple mailing lists at once Ask others to debug your broken code without giving a hint as to what sort of problem they should be searching for · · · · · 10/14
- 11. Case Study: A Recent Post to the R-devel Case Study: A Recent Post to the R-devel Mailing List Mailing List Subject: large dataset - confused Message: I'm trying to load a dataset into R, but I'm completely lost. This is probably due mostly to the fact that I'm a complete R newb, but it's got me stuck in a research project. 11/14
- 12. Response Response Yes, you are lost. The R posting guide is at http://www.r-project.org/posting- guide.html and will point you to the right list and also the manuals (at e.g. http://cran.r-project.org/ manuals.html, and one of them seems exactly what you need). 12/14
- 13. Analysis: What Went Wrong? Analysis: What Went Wrong? Question was sent to the wrong mailing list (R-devel instead of R-help) Email subject was very vague Question was very vague Problem was not reproducible No evidence of any effort made to solve the problem RESULT: Recipe for disaster! · · · · · · 13/14
- 14. Places to Turn Places to Turn Class discussion board; your fellow students r-help@r-project.org Other project-specific mailing lists (This talk inspired by Eric Raymond’s “How to ask questions the smart way”) · · · 14/14