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| Software Engineering Series |
“Two heads are better than one” – a proverb whose wisdom is embraced today in the various forms of harnessing the collective intelligence. The use of groups in problem solving is based on principles like “the collective is more than the sum of its individuals” or that “the crowds are better on average at estimations than the experts”. All well and good, based on the rationality of the same proverb has been advanced the idea of having two developers working together on the same piece of code – one doing the programming while the other looks over the shoulder as a observer or navigator (whatever that means), reviewing each line of code as it is written, strategizing or simply being there.
This approach is known as pair programming and considered as an agile software development technique, adhering thus to the agile principles (see the agile manifesto). Beyond some intangible benefits, its intent is to reduce the volume of defects in software and thus ensure an acceptable quality of the deliverables. It’s also an extreme approach of the pear review concept.
Without considering whether pair programming adheres to the agile principles, the concept has several big loopholes. The first time I read about pair programming it took me some time to digest the idea – I was asking myself what programmer will do that on a daily basis, watching as other programmers code or being watched while coding, each line of code being followed by questions, affirmative or negative nodding… Beyond their statute of being lone wolves, programmers can cooperate when the tasks ahead requires it, however to ask a programmer watch actively as others program it won’t work on the long run!
Talking from my own experience as programmer and of a professional working together with other programmers, I know that a programmer sees each task as a challenge, a way of learning, of reaching beyond his own condition. Programming is a way of living, with its pluses and minuses.
Moreover, the complexity of the tasks doesn’t resume at handling the programming language but of resolving the right problem. Solving the right problem is not something that can one overcome with brute force but with intelligence. If using the programming language is the challenge then the problem lies somewhere else and other countermeasures must be taken!
Some studies have identified that the use of pair programming led to a reduction of defects in software, however the numbers are misleading as long they compare apples with pears. To statistically conclude that one method is better than the other means doing the same experiment with the different methods using a representative population. Unless one addressees the requirements of statistics the numbers advanced are just fiction!
Just think again about the main premise! One doubles the expenditure for a theoretical reduction of the defects?! Actually is more than double considering that different types of communication takes place. Without a proven basis the effort can be somewhere between 2.2 and 2.5 and for an average project this can be a lot! The costs might be bearable in situations in which the labor is cheap, however programmers’ cooperation is a must.
The whole concept of pair programming seems like a bogus idea, just like two drivers driving the same car! This approach might work when the difference in experience and skills between developers is considerable, that being met in universities or apprenticeship environments, in which the accent is put on learning and forming. It might work on handling complex tasks as some adepts declare, however even then is less likely that the average programmer will willingly do it!
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