3 June 2014
Guidelines for Effective Pair Programming
Pair programming is an agile software development technique in which two programmers work together at one workstation. One, the driver, writes code while the other, the observer, pointer or navigator, reviews each line of code as it is typed in. The two programmers switch roles frequently.1
Pair programming is one of many techniques we use at Gaslight for producing high quality software. Teams are not required to pair all the time, but it can be effective in certain situations. Below are some guidelines that have emerged from our experience with pair programming.
Shared Workstation / Physical Environment
If you opt to share a physical workspace while pair programming there are extra considerations to take into account. Dedicated pairing stations that are not owned by a single developer can help reduce some of these problems.
Avoiding Poor Ergonomics
When pairing, it is not always important to be sitting at the same desk. Many of us have found that sharing a single desk with another person leads to poor posture. People of different sizes have unique desk and chair height needs, it can be difficult to accommodate both individuals. Sharing a single display causes your neck to be turned for long periods of time.
Posture and ergonomics is important and it should be taken into consideration any time you’re at a workstation. Using ScreenHero or the native Mac OS screen sharing while sitting diagonal from one another has worked well for us. Sitting diagonal from one another also allows you to see one another without twisting sideways.
- Brush your teeth
- Wear deodorant
Don’t share a workspace if you’re sick, you shouldn’t even be at the office. You’ll most likely end up getting your pair sick and decrease the productivity of the team.
- Free of clutter
- Sanitized (alcohol wipes are your friend)
Dedicated pair programming stations reduce some of these issues, but they’re not always practical.
The physical environment is not the only important factor when pairing, the virtual environment is also important. These tips are also tips for general productivity and can be applicable when working without a pair.
No extra windows
Close any windows not related to the problem that you’re working on currently. Extra text editor windows, email, unrelated browser tabs or windows, and anything else should not be open. Extra windows cause distraction and make using alt-tab to switch through applications more difficult.
Both pairs need to be effective with the text editors that is being used during the pairing session. If you both use Vim during your normal day, feel free to use it. Consider adding a custom vimrc and sourcing it to give your pair keybindings they’re comfortable with. If one of you uses Vim and the other Emacs, you shouldn’t argue about which editor to use, pick something neutral. We like Atom.
Come up with a sane window layout so that you can see what’s important and have fast feedback loops. Moom gives you the ability to save and restore window layouts. It also has a nice grid for resizing and moving windows into position.
Close Email, Close Chat
Pair programming is not the time to catch up on email or chat with your significant other about what’s for dinner tonight. You’re wasting your time and your pair’s time if you do this.
Turn Off Notifications
If you’re using Mac OS you should turn off notifications (option-click notification center).
Keep a notepad on the desk so you don’t have to interrupt your pair when you notice something that you need to do later.
Turn Off Your Phone
Like email and instant messaging, your phone is an unnecessary distraction and shouldn’t be in your hand while pairing. You’re supposed to be engaged in the process and if your phone is in hand, you won’t be.
Bounce back and forth frequently. It is not effective to have one person driving the whole time. The person who isn’t coding is likely to end up bored and you won’t realize the full benefits of pair programming.
Avoid Conversation With Others
We are working in a mostly open office space and if you’re talking with someone else while your pair is working, you’re not helping the cause.
Know Your Tools
This is important whether you’re pairing or working by yourself. It’s important to understand the tools you’re working with.
Often times there are tasks which are rather mundane that are not challenging. Know when you should pair up and when it may be better to work on your own. Remember that when you’re pairing you’re using two people’s time.