Two team members participate in one development effort at one workstation or table
Developing In Pairs is a generalization of the XP core practice of Pair Programming.†
There are many beneficial aspects of developing in pairs.† These include instant communication, constant peer review, the ability to bring skill combinations to bear on a problem that do not naturally belong in any single team member, flexibility of resources, constant skills transfer, dissemination of knowledge of parts of the system outside an individualís specialist area/s, reduced likelihood to drift off topic, etc.† It is assumed that when developing in pairs, there will be some mechanism to ensure a pair has, between them, the relevant expertise to perform the task.† Pairing typically lasts about a couple of hours, though this could be longer or shorter depending on the task being undertaken.
The initial response from a newcomer to the concept tends to be negative in that it now takes two people to do what previously only took one person.† Studies have shown that Pair Programming does not reduce productivity once suitable working practices are learned, and this takes approximately 3 weeks.† There is good reason to suppose such results would also apply to the wider practice of Developing In Pairs.
There has been much discussion and considerable volume of published material on Pair Programming related to XP, that covers the issues in considerably greater depth.