how best are best practices?

November 25, 2009

You may have heard the flutter over UNAIDS’s report showing 17% reductions in HIV prevalence in sub-Saharan Africa. Sounds like good news all around, right? Well, here are brief thoughts on a few concerns i have about those figures.

  • i haven’t read the methods for the estimation closely, but it’s highly probable that some shifting population dynamics may be part of the story (e.g., recent declines in fertility – albeit modest – may be reducing the number of susceptibles sufficiently to shift the population structure enough to appear like a reduction when it’s not really one; similarly i don’t know how shifts in AIDS-specific mortality, have been accounted for either).
  • Perhaps more problematically for these estimates, given things that i have encountered personally in field work in Malawi, is the fact that those who know they are positive are more likely to refuse additional testing in the future. And with the – again, albeit limited – uptick in testing in many countries in SSA recently, the declines may be in part reflecting those refusals more than an actual drop in prevalence (see dadakim for more on this point).
  • i’d prefer to not always play the pessimist, i just think that this one should be read a bit cautiously.


    standards in publishing

    November 24, 2009

    In the comments on a previous post, dadakim raises a pertinent question about publishing practices that hasn’t (yet?) been adopted in sociology (other than by SMR*, as far as i know). I re-raise it here in case you missed it because i’d be interested in reader reactions to the idea.

    But the motivation for this post was actually an unrelated publishing issue has been bugging me for a while. Why is it that news articles that mention scientific research don’t have to detail their sources? This is one practice i’ve never understood. I get elated when i see articles that actually go ahead and source the original materials, which is sad, since i think it should be SOP.

    *See the last paragraph of the guidelines.

    Does Class Exist?

    November 24, 2009

    In Dennis Condron’s new ASR article on academic achievement he writes:

    “The second contribution [of this article] lies in conceptualizing and analyzing social class rather than socioeconomic status (SES).  This reflects the view that children growing up in different positions in the stratification hierarchy have categorically unequal and qualitatively different (rather than continuously graded) life and educational experiences.”

    What evidence exists for this claim?  To me, this is the sort of claim that the paper should explore empirically, but let’s go ahead and see how he measures social class:

    “I [Condron] code children as middle/upper class if either parent has a bachelor’s degree or higher or works in an executive, administrative, or managerial position and their household income is above the federal poverty line.  Children are coded working class if both parents have less than a bachelor’s degree and do not work in an executive, administrative, or managerial position and their household income is above the poverty line.  Finally, I code students as poor if their household income is below the poverty line, regardless of parents’ education levels and job positions.”

    Then he examines the relationship between the class categories he created and academic achievement.

    The standard objection to this approach is that it is throwing away data, the class categories hide important differences.  Whether you have one or two parents with a B.A. does not enter the analysis.  If your parents’ income is under the poverty line, their education is ignored.  Income differences above the poverty line are ignored, etc.

    If I reanalyzed the data using parental income, education, and occupation, instead of class, I would be able to explain more variation in academic achievement.  There are times when I am more willing to “throw away” data, for example when I’m desperate for more degrees of freedom, but even then I feel bad about it.

    This provocative blog post title: “Does class exist?” drew inspiration from Daniel Little.  I’m curious to see if it attracts more clicks.  It would probably be more to the point to ask whether the concept of discrete social classes is useful.  If it does not help one predict outcomes of interest, then I think not.

    an (un)happy medium

    November 23, 2009

    As seen here (via KD), a quite dramatic and clear example of when the mean isn’t sufficient for telling the whole story is arising over at Amazon in the rankings of Going Rogue. Not surprising, i know. But still.

    when is throwing money at the problem the better solution?

    November 21, 2009

    Wow, here‘s a pretty dramatic suggestion (from mathematical modelers) about how to curb HIV. Though i think my attention may have been drawn even more strongly to the part of the story that makes not using upper case letters in my name possibly seem pretty normal by comparison.

    this is not how i expected “friending” you to come back to haunt me

    November 19, 2009

    This story‘s been making the rounds rather quickly. For now, i’ll link it sans commentary. Basically it’s a company that’s claiming to be able to make inferences about individuals’ credit ratings based solely on their social networks as publicly observable through Facebook, Twitter, etc.
    (via Keith Hampton and Valdis Krebs)

    Are Social Networks Fundamental?

    November 19, 2009

    Are social networks fundamental?  That is how Daniel Little frames this interesting post.  At first, I wasn’t quite sure what he meant.  I thought, “No, social networks can’t be understood without understanding the people that comprise them, the society they exist within, etc.,” but then I actually started reading his post and realized he is asking whether the concept of a social network is central to most social explanation.  This is something I am more inclined to agree with.  Was I the only one briefly thrown for a loop by that title?

    Jeremy Freese on Blogging and Public Intellectuals

    November 17, 2009

    From a short article in the journal Society by Jeremy Freese:

    Blogs are distinct from their predecessors for the pervasiveness of quotation and the extent to which authors keep your attention by continually directing it elsewhere. If one thinks in terms of the services that public intellectuals contribute—new ideas, means of making sense of the events of our times, moral conscience—than the important question is whether the new model of decentralized collaboration provides these services better than a model in which a few erudite individuals are identified as the souls of the age.

    The answer is yes.

    The Most Interesting Scholar in the World

    November 16, 2009

    I imagine everyone is now familiar with the Dos Equis commercials.  Peter Klein’s adaptation is The Most Interesting Scholar in the World:

    His work would pass peer review . . . if he had peers.

    Football players at his university have season tickets to his lectures.

    …Stay thirsty for knowledge, my friends.

    There are a bunch more funny ones if you follow the link above.

    assessing peer review

    November 13, 2009

    Here’s an interesting paper (may require login) from the Journal of the Royal Society of Medicine. From the abstract:

    Design 607 peer reviewers at the BMJ were randomized to two intervention groups receiving different types of training (face-to-face training or a self-taught package) and a control group. Each reviewer was sent the same three test papers over the study period, each of which had nine major and five minor methodological errors inserted.
    Results The number of major errors detected varied over the three papers.The interventions had small effects. At baseline (Paper 1) reviewers found an average of 2.58 of the nine major errors, with no notable difference between the groups.The mean number of errors reported was similar for the second and third papers, 2.71 and 3.0, respectively. Biased randomization was the error detected most frequently in all three papers, with over 60% of reviewers rejecting the papers identifying this error. Reviewers who did not reject the papers found fewer errors and the proportion finding biased randomization was less than 40% for each paper.

    The thing is, i am having a relatively difficult time convincing myself that the comparison they made is the interesting one. When reviewing a paper, are we really ever looking for all of the errors in the piece or just enough to sufficiently determine whether to accept/reject the article? So, how interesting is the difference in the “number of errors found” among those who rejected the paper? To me, not very. This doesn’t undermine their conclusion:

    Conclusions Editors should not assume that reviewers will detect most major errors, particularly those concerned with the context of study. Short training packages have only a slight impact on improving error detection.

    My question is do you find the question interesting, or would you have sliced the data a different way?

    (HT: Michelle Poulin)