Update - I've written Yet Another blog post, More on scientific software on this topic. I think this blog post is a mess so you should read that one first ;).
This blog post was spurred by a simple question from Pauline Barmby on Twitter. My response didn't, ahem, quite fit in 144 characters :).
First, a little story. (To paraphrase Greg Wilson, "I tell a lot of stories. Some of them aren't true. But this one is!")
When we were done writing Best Practices for Scientific Computing, we tried submitting it to a different high-profile journal than the one that ultimately accepted it (PLoS Biology, where it went on to become the most highly read article of 2014 in PLoS Biology). The response from the editor went something like this: "We recognize the importance of good engineering, but we regard writing software as equivalent to building a telescope - it's important to do it right, but we don't regard a process paper on how to build telescopes better as an intellectual contribution." (Disclaimer: I can't find the actual response, so this is a paraphrase, but it was definitely a "no" and for about that reason.)
Is scientific software like instrumentation?
When I think about scientific software as a part of science, I inevitably start with its similarities to building scientific instruments. New instrumentation and methods are absolutely essential to scientific progress, and it is clear that good engineering and methods development skills are incredibly helpful in research.
So, why did the editors at High Profile Journal bounce our paper? I infer that they drew exactly this parallel and thought no further.
But scientific software is only somewhat like new methods or instrumentation.
First, software can spread much faster and be used much more like a black box than most methods, and instrumentation inevitably involves either construction or companies that act as middlemen. With software, it's like you're shipping kits or plans for 3-D printing - something that is as close to immediately usable as it comes. If you're going to hand someone an immediately usable black box (and pitch it as such), I would argue that you should take a bit more care in building said black box.
Second, complexity in software scales much faster than in hardware (citation needed). This is partly due to human nature & a failure to think long-term, and partly due to the nature of software - software can quickly have many more moving parts than hardware, and at much less (short term) cost. Frankly, most software stacks resemble massive Rube Goldberg machines (read that link!) This means that different processes are needed here.
Third, at least in my field (biology), we are undergoing a transition to data intensive research, and software methods are becoming ever more important. There's no question that software is going to eat biology just like it's eating the rest of the world, and an increasingly large part of our primary scientific output in biology is going to hinge directly on computation (think: annotations. 'nuff said).
If we're going to build massively complex black boxes that under-pin all of our science, surely that means that the process is worth studying intellectually?
Is scientific software a primary intellectual output of science?
I think concluding that it is is an example of the logical fallacy "affirming the consequent" - or, "confusion of necessity and sufficiency". I'm not a logician, but I would phrase it like this (better phrasing welcome!) --
Good software is necessary for good science. Good science is an intellectual contribution. Therefore good software is an intellectual contribution.
Hopefully when phrased that way it's clear that it's nonsense.
I'm naming this "the fallacy of grad student hackers", because I feel like it's a common failure mode of grad students that are good at programming. I actually think it's a tremendously dangerous idea that is confounding a lot of the discussion around software contributions in science.
To illustrate this, I'll draw the analog to experimental labs: you may have people who are tremendously good at doing certain kinds of experiments (e.g. expert cloners, or PCR wizards, or micro-injection aficionados, or WMISH bravados) and with whom you can collaborate to rapidly advance your research. They can do things that you can't, and they can do them quickly and well! But these people often face dead ends in academia and end up as eterna-postdocs, because (for better or for worse) what is valued for first authorship and career progression is intellectual contribution, and doing experiments well is not sufficient to demonstrate an intellectual contribution. Very few people get career advancement in science by simply being very good at a technique, and I believe that this is OK.
Back to software - writing software may become necessary for much of science but I don't think it should ever be sufficient as a primary contribution. Worse, it can become (often becomes?) an engine of procrastination. Admittedly, that procrastination leads to things like IPython Notebook, so I don't want to ding it, but neither are all (or even most ;) grad students like Fernando Perez, either.
Let's admit it, I'm just confused
This leaves us with a conundrum.
Software is clearly a force multiplier - "better software, better research!.
However, I don't think it can be considered a primary output of science. Dan Katz said, "Nobel prizes have been given for inventing instruments. I'm eagerly awaiting for one for inventing software [sic]" -- but I think he's wrong. Nobels have been given because of the insight enabled by inventing instruments, not for inventing instruments. (Corrections welcome!) So while I, too, eagerly await the explicit recognition that software can push scientific insight forward in biology, I am not holding my breath - I think it's going to look much more like the 2013 Chemistry Nobel, which is about general computational methodology. (My money here would be on a Nobel in Medicine for genome assembly methods, which should follow on separately from massively parallel sequencing methods and shotgun sequencing - maybe Venter, Church, and Myers/Pevzner deserve three different Nobels?)
Despite that, we do need to incentivize it, especially in biology but also more generally. Sean Eddy wrote AN AWESOME BLOG POST ON THIS TOPIC in 2010 (all caps because IT'S AWESOME AND WHY HAVEN'T WE MOVED FURTHER ON THIS <sob>). This is where DOIs for software usually come into play - hey, maybe we can make an analogy between software and papers! But I worry that this is a flawed analogy (for reasons outlined above) and will simply support the wrong idea that doing good hacking is sufficient for good science.
We also have a new problem - the so-called Big Data Brain Drain, in which it turns out that the skills that are needed for advancing science are also tremendously valuable in much more highly paid jobs -- much like physics number crunchers moving to finance, research professors in biology face a future where all our grad students go on to make more than us in tech. (Admittedly, this is only a problem if we think that more people clicking on ads is more important than basic research.) Jake Vanderplas (the author of the Big Data Brain Drain post) addressed potential solutions to this in Hacking Academia, about which I have mixed feelings. While I love both Jake and his blog post (platonically), there's a bit too much magical thinking in that post -- I don't see (m)any of those solutions getting much traction in academia.
The bottom line for me is that we need to figure it out, but I'm a bit stuck on practical suggestions. Natural selection may apply -- whoever figures this out in biology (basic research institutions and/or funding bodies) will have quite an edge in advancing biomedicine -- but natural selection works across multiple generations, and I could wish for something a bit faster. But I don't know. Maybe I'll bring it up at SciFoo this year - "Q: how can we kill off the old academic system faster?" :)
I'll leave you with two little stories.
The problem, illustrated
In 2009, we started working on what would ultimately become Pell et al., 2012. We developed a metric shit-ton of software (that's a scientific measure, folks) that included some pretty awesomely scalable sparse graph labeling approaches. The software worked OK for our problem, but was pretty brittle; I'm not sure whether or not our implementation of this partitioning approach is being used by anyone else, nor am I sure if it should be :).
However, the paper has been a pretty big hit by traditional scientific metrics! We got it into PNAS by talking about the data structure properties and linking physics, computer science, and biology together. It helped lead directly to Chikhi and Rizk (2013), and it has been cited a whole bunch of times for (I think) its theoretical contributions. Yay!
Nonetheless, the incredibly important and tricky details of scalably partitioning 10 bn node graphs were lost from that paper, and the software was not a big player, either. Meanwhile, Dr. Pell left academia and moved on to a big software company where (on his first day) he was earning quite a bit more than me (good on him! I'd like a 5% tithe, though, in the future :) :). Trust me when I say that this is a net loss to academia.
Summary: good theory, useful ideas, lousy software. Traditional success. Lousy outcomes.
In 2011, we figured out that linear compression ratios for sequence data simply weren't going to cut it in the face of the continued rate of data generation, and we developed digital normalization, a deceptively simple idea that hasn't really been picked up by the theoreticians. Unlike the Pell work above, it's not theoretically well studied at all. Nonetheless, the preprint has a few dozen citations (because it's so darn useful) and the work is proving to be a good foundation for further research for our lab. Perhaps the truest measure of its memetic success is that it's been reimplemented by at least three different sequencing centers.
The software is highly used, I think, and many of our efforts on the khmer software have been aimed at making diginorm and downstream concepts more robust.
Summary: lousy theory, useful ideas, good software. Nontraditional success. Awesome outcomes.
I simply don't know how to chart a course forward. My current instinct (see below) is to shift our current focus much more to theory and ideas and further away from software, largely because I simply don't see how to publish or fund "boring" things like software development. (Josh Bloom has an excellent blog post that relates to this particular issue: Novelty Squared)
I've been obsessing over these topics of software and scientific focus recently (see The three porridge bowls of scientific software development and Please destroy this software after publication. kthxbye) because I'm starting to write a renewal for khmer's funding. My preliminary specific aims look something like this:
Aim 1: Expand low memory and streaming approaches for biological sequence analysis.
Aim 2: Develop graph-based approaches for analyzing genomic variation.
Aim 3: Optimize and extend a general purpose graph analysis library
Importantly, everything to do with software maintenance, support, and optimization is in Aim 3 and is in fact only a part of that aim. I'm not actually saddened by that, because I believe that software is only interesting because of the new science it enables. So I need to sell that to the NIH, and there software quality is (at best) a secondary consideration.
On the flip side, by my estimate 75% of our khmer funding is going to software maintenance, most significantly in paying down our technical debt. (In the grant I am proposing to decrease this to ~50%.)
I'm having trouble justifying this dichotomy mentally myself, and I can only imagine what the reviewers might think (although hopefully they will only glance at the budget ;).
So this highlights one conundrum: given my estimates and my priorities, how would you suggest I square these stated priorities with my funding allocations? And, in these matters, have I been wrong to focus on software quality, or should I have focused instead on accruing technical debt in the service of novel ideas and functionality? Inquiring minds want to know.