Showing posts with label peer review. Show all posts
Showing posts with label peer review. Show all posts

Sunday, November 29, 2009

How And When To Read A Scientific Paper As A Layman

Science is conducted by people, most of whom are bright, a fraction are very bright, and a small fraction are brilliant. These people are, as discussed in the post Peer Review & Skepticism competing for prestige and grant money. The vast majority of papers are rushed at the end to get them ready for presentation at conferences.

The paper publication process starts with publication and presentation at a conference. The paper is distributed to all conference attendees, who hopefully read it before your presentation on it, and there's usually a question and answer phase afterwards.

The paper gets commented on (generally by email) from attendees who read it, went through the presentation, and had questions or insights.

Most paper presenters incorporate those comments into the next draft of the paper (or, sometimes, decide that the line of research needs to be abandoned), and then submit it for peer review and publication in a journal.

Once the paper is in the journal, there will usually be a journal moderated commentary and letters section, where a second round of "let's make sure this says what you think it says" comes into play, usually with responses by the original author put back in.

In a lot of ways, it behaves like USENET discussion groups, but more slowly and with a bit more deliberation in the outcome. (And yes, it has its flame wars and trolls.)

Scientific papers have an abstract, a number of chapters or sections, and a set of end notes. If you're not used to reading them, the abstract is a one or two paragraph summary of what's to be covered in the paper, the notes cover where their sources are, accredit people whose work they've referenced, and sometimes point to "Unpublished Annexes" that give people the ability to dig deeper if they're interested.

This means that - as a layman - you should start reading papers when they have their journal mandated Question and Response come through. This also means, between conference presentations and journal review and question and response that anything that's published within the last 9 months is still probably waiting for that commentary process to run through.

It will also be a difficult read. Most scientists are, to put it mildly, mediocre writers. Science papers also have a particular formalism that makes perfect sense in context, but explains why scientists generally can't write.

The ideal is that the authorial voice comes out to "Experiment X was run in methodologies Y, with results Z, the conclusions derived from the data are ...". This is the near inverse of journalistic writing, where you'd start with the conclusion, work your way through the data gathering, then gloss over the methodologies, and show how the results supported the conclusion.

Just because it's difficult doesn't mean you shouldn't do it, but you should, as a layman, budget time to look over related papers. You cannot read one paper in isolation and get a realistic appreciation of what's going on.

Tuesday, November 24, 2009

Peer Review & Skepticism

One of the places where fringe-science and junk-science attempt to grab credibility is through the peer review process. Peer review nominally works like this:

You do research (or what's called a literature review - more on that later). You write your paper. You submit it to a journal. The journal sends it out to other people in the field who read it and say "This is interesting" or "This confirms what we already know" or "This was written by someone with an axe to grind" or "This was written by a guy who makes the TimeCube hypothesis seem sane."

Publication in peer reviewed journals is competitive; an academic's professional reputation (salary, grants, interesting research projects) is based on getting published in peer reviewed journals. One side effect of this is that getting your article in the journals first is an important consideration. Much like Internet news versus newspapers, the person who breaks the story wins the race.

And science is a LOT of hard work. Most people who don't do science for a living have no clue how much work goes into it, or how difficult that work is. Anyone who flailed at second semester Calculus in high school or college, or who found doing lab notes in physics class to be about as interesting as whacking their hand with a hammer has the vague inkling that this is difficult.

It's even worse for actual practicing scientists. Take your "beat my head against Calculus" moments, combine with "gather data with instruments, and record error bars" for two years and THEN race to get your results out so that you get the A and someone else doesn't - provided nobody spots a nitpicky thing you overlooked early in setting up your experiment design. You're also usually rushing to get your paper ready for the submission deadline for a conference.

Oh, and if you don't win approximately 1/3 of the races, you lose your job.

This results in two incentives in behavior. As a game designer, I've found that you reliably get the behavior you incentivize.

Incentive 1: Until you're close to publication, you say nothing about what you're researching, your preliminary results, etc.

Incentive 2: You submit papers to journals that you think will agree with your outcome. Subsequently, peer reviewed journals have a strong tendency towards confirmation bias.

Now, actual science is hard, even when researchers have grad students in near peonage to do the scut-work for them. Cranks show up in peer review journals not with actual research (because that requires data set gathering, computation and rigorous analysis - and more to the point, takes time), but with something called 'Literature Analysis'.

In scientific journals, Literature Analysis means combing through related studies and their data sets and looking for contradictions or gaps; either one is a marker for "Hey, there's something interesting to research going on."

Literature reviews are more common in the worlds of law - in literature reviews, you go through the published papers and draw conclusions that match your pre-supposing condition. A lawyer that brought up things contrary to his own case would be laughed at; a scientist who doesn't has some professional quandaries to consider.

Which leads us back to the CRU data leak. One of the places where high dudgeon is being raised is over the work of Jones, Goodess, Mann et al to get Climate Research Journal 'shunned from the peer review list'.

The article that triggered this reaction was a "Literature review" by policy wonks Willie Soon and Sallie Baliunas. The review was a very selective set of cherrypicking, and was a pure political hatchet job. It's difficult to get things past the confirmation bias on a politicized issue...but Jones and Mann, in this instance, were doing what peer review is supposed to do - point out when something slipped through that should not have gotten through.

There is real, legitimate skepticism about climate science out there. There are also a lot of cranks and political hacks trying to cloak their propaganda in the trappings of skepticism. Just like we should be dubious about the people who say "Your SUV is KILLING US ALL", we should be dubious about skepticism that doesn't do its own research, or is a Trojan horse for political activism.