Computer Floss

And so, we revisit the posers put up in a previous post:

1. Are Debian’s evolutionary characteristics significantly different to those of SourceForge?
2. Does Debian act as a catalyst?

To answer these questions, we took a closer look at the software inside them. I’ll briefly explain the method here, but details of the steps will be part of later posts in the “Research Methods” strand.

We chose a mutually exclusive sample of 50 packages from Debian and 50 projects from SourceForge.  In both cases they were taken from the pool of “stable” projects only. They were all downloaded and each project’s activity was extracted from their version control system (using log commands) and recorded in a file. Then we delved into our little toolbox and used some nifty tools to extract the information we needed, that information being the project’s:

• Age (time between first and last commit to the version control system)
• Size (in lines of code)
• Number of developers (monthly average)
• Number of commits (monthly average)

Each attribute can be aggregated from the 50 projects into a summary value for the repository. So, for example, we can take the ages of the 50 Debian projects and use them to get a mean or a median age. If we do the same thing for SourceForge we can compare them.

And that’s just what we did.

And here’s just what we found:

Boxplots of measured attributes

Using statistical significance testing (again, I’ll cover this in a “Research Methods” post) we found that Debian projects had larger values for each attribute, i.e. they were older, larger, and attracted more developers who peformed a greater amount of work, all to a significant degree.

This leads us to our second question, is Debian responsible? Is it somehow a driver for these larger values? Our answer to this question comes in round 3.

We all know about SourceForge and Debian. Although they have different purposes, they both act as repositories of free software, and most of the practitioners will know that Debian hosts what is considered to be the best projects — judged most worthy by its army of package maintainers. Conversely, many (but by no means all) SourceForge projects languish in obscurity; these are, at best, of little interest outside of the developers who run them, or, at worst, have completely stalled. It is conventional wisdom then that Debian projects receive much more activity from developers than those on communities like SourceForge.

So today’s research question is: How true is this? How much more activity (if at all) do projects in Debian actually receive than their counterparts in SourceForge? To answer this query, two quantifiable and measurable questions are proposed:

1. Are the evolutionary characteristics of Debian projects significantly different from those in SourceForge? (In other words, do Debian projects receive so much more activity that we cannot conclude that random statistical noise is responsible for the difference?)
2. Does Debian act as a “catalyst”, so that when project are entered into Debian’s repository, the activity around the project increases?

To answer the questions, we need to measure proxies of evolutionary activity. We chose:

• Project age
• Project size
• Number of developers
• Number of commits

How these attributes were measured, and how they helped to answer the questions, will be addressed in the follow-up post.