17.181 new on WWW: Critical Thinking; CIT Infobits 7/03

From: Humanist Discussion Group (by way of Willard McCarty willard.mccarty@kcl.ac.uk)
Date: Tue Aug 05 2003 - 01:26:49 EDT

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                   Humanist Discussion Group, Vol. 17, No. 181.
           Centre for Computing in the Humanities, King's College London
                         Submit to: humanist@princeton.edu

       [1] From: tgelder@trinity.unimelb.edu.au (182)
             Subject: latest additions to Critical Thinking on the Web

       [2] From: kotlas@email.unc.edu (22)
             Subject: CIT Infobits -- july 2003

             Date: Tue, 05 Aug 2003 06:12:10 +0100
             From: tgelder@trinity.unimelb.edu.au
             Subject: latest additions to Critical Thinking on the Web

    21 July

    in Textbooks

    <http://www.as.wvu.edu/~sbb/comm221/primer.htm>Steve's Primer of Practical
    Persuasion and Influence by Steve Booth-Butterfield
    An online textbook on persuasion, influence and attitude. Developed for
    use in a university course. Very "bare bones" (no pictures) but written in
    a very accessible, colloquial style. [21 July 03]

    18 July

    in The Enlightenment

    <http://www.nytimes.com/2003/07/12/opinion/12DENN.html>The Bright Stuff by
    Daniel Dennett
    Come out as a bright. "What is a bright? A bright is a person with a
    naturalist as opposed to a supernaturalist world view. We brights don't
    believe in ghosts or elves or the Easter Bunny or God." Being a bright is
    not quite the same as being a critical thinker, but they are closely
    aligned. (Yes, I count myself a bright.) [18 July 03]

    5 July

    in Guides

    <http://vm.uconn.edu/~wwwphil/logic.pdf>A Quick Introduction to Logic by
    Scott Lehmann
    A 29 page document (pdf file) covering the basics of logic. Too succinct
    and technical to be much use the first time you try to learn about logic,
    but may be handy for someone wanting to refresh on core topics. [5 Jul 03]

    24 Jun

    in The Enlightenment (new section)

    of reason By Darrin M. McMahon
    Reviewing the Encyclopedia of the Enlightenment is just the pretext for
    this excellent, highly compact overview of the Enlightenment and reactions
    to it. [24 Jun 03]

    in Experts and Expertise - Literary Critics, and Language and Thought

    <http://www.theatlantic.com/issues/2001/07/myers.htm>A Reader's Manifesto
    by B.R. Myers.
    Scathing attack on the sloppy thinking behind the pretentiously literary
    style of today's acclaimed fiction, and on the goggle-eyed idiocy of
    critics who applaud it. "Nothing gives me the feeling of having been born
    several decades too late quite like the modern "literary" best
    seller...Clumsy writing begets clumsy thought, which begets even clumsier
    writing. The only way out is to look back to a time when authors had more
    to say than "I'm a Writer!"; when the novel wasn't just a 300-page caption
    for the photograph on the inside jacket." [24 Jun 03]

    18 Jun

    in Guides


    Guide for the U.S. Customs Service Critical Thinking Skills Test (Word
    You may well find this useful even if you're not applying for promotion in
    the US Customs Service. Much of the document consists of a fairly
    technical introduction to basic logic. Working through this study guide
    would probably be good preparation for a range of standard tests involving
    logical thinking, eg the LSAT. [18 Jun 03]

    14 Jun

    in Language and Thought

    "Stripping the bull out of business." This program works like a
    spell-checker, but helps you remove consultant-speak (leverage, mindshare,
    etc.) from your documents. From Deloitte Consulting, who were partly
    responsible for creating the problem in the first place. At least they're
    giving it away free. [14 Jun 03]


    Hans Farkas sent the following interesting query. It is not about critical
    thinking as such, but it does involve applying critical thinking. Please
    respond directly to Hans, hfarkas@yahoo.com

    I would like to know if anyone has come across
    information describing the fallacies of "ballistics
    experts" testifying that they can positively identify
    a gun via comparison of the markings on a test bullet
    fired from that gun, and a bullet recovered from the
    scene of the crime.

    I have never seen a challenge to these claims, but
    from what I know about how guns are manufactured,
    specifically, how the rifling (i.e., grooves and
    lands) is cut into the barrel, the "expert" claims of
    being able to match a specific gun to a crime have got
    to be wrong. Here's why.

    The rifling is cut into the barrel via a hardened
    cutter die, called a button, which has the design
    ground into it, and when it is pulled or pressed
    through the barrel's smooth bore, it cuts the high
    and low spirals (called rifling) into the barrel. Now
    this cutter die (i.e., button) is either made from
    hardened tool steel, or perhaps tungsten carbide. At
    any rate, the same button is used to cut the rifling
    into many barrels. How many times a specific button
    can be used before it is worn out depends on a number
    of factors, and a tungsten carbide cutter will last
    considerably longer than a tool steel cutter.
    But certainly a significant number of barrels are
    rifled by the same button. And the number of barrels
    a specific button can rifle is probably in the
    hundreds, and perhaps even in the thousands, before it
    has to be replaced.

    What this means is that essentially all the barrels of
    a specific manufacturing run that are cut by the same
    button, are going to have the same rifling pattern.
    Undoubtedly, assuming that the same button can be used
    on 1,000 barrels, there might be a microscopic
    difference in the sharpness of the cut when comparing
    the first barrel with the thousandth one. But surely
    there is no practically distinguishable difference
    between between the first 100 barrels with each other,
    or between the last hundred with each other. In other
    words, while one might distinguish a microscopic
    difference between the first barrel as compared to
    barrel number 999, surely the difference between the
    first barrel and the second barrel, etc., are
    virtually indistinguishable.

    If this is true, then the "experts" claiming that a
    positive identification was made are actually only
    able to say (in the best case, assuming they have made
    a careful comparison) that the bullet recovered at the
    scene of the crime probably came from a gun
    manufactured by the same button as the gun in
    question. In other words, instead of claiming it is
    the same gun, they are only able to state (if they are
    honest and competent) that one of hundreds of guns
    from the same manufacturing run could be the actual
    gun. Furthermore, it is probable that even if
    multiple buttons are used in a specific manufacturing
    run (i.e., same model and year of manufacture), each
    button is made to the same close tolerances and
    design. This would make it impossible to distinguish
    the grooves made even from a group of buttons, from
    each other, certainly by the relatively crude methods
    of comparison (low-power microscopic alignment of
    rifling) used by these experts.

    Realistically, it is one thing to distinguish between
    a bullet from a Smith & Wesson 38 caliber, from a Colt
    38 caliber since each manufacture is making his own
    buttons, undoubtedly to different designs. And
    probably different models of the same caliber from the
    same manufacture, or from different years of
    manufacture are distinguishable. But to distinguish
    between any one of a thousand barrels rifled by the
    same button is probably not possible in the way these
    "experts" do their comparison. Undoubtedly on a
    theoretical basis, say with very high magnifications
    of electron microscopes it might be possible to
    actually distinguish, for example barrel number 48
    from barrel number 49, by seeing extremely minute
    changes in the button due to wear. But that is not
    how these "experts" practice their craft.

    It is one thing to use this type of comparison to
    exclude a gun, but quite another to be able to state
    with certainty it is the same gun. For example, if
    the gun is a 38 caliber and the bullet recovered from
    the crime scene is a 44 caliber, it is easy to be
    certain that they are mutually exclusive. Similarly,
    in the case of the same caliber comparison, if the
    rifling does not match (perhaps because the grooves
    are of a different number, or the depths are
    different, or the widths differ), exclusion can be
    done with certainty. But if everything matches, the
    best that can be stated is that they are similar
    enough to be from the same make and model, or even
    from the same manufacturing run. But that may mean
    there are thousands of other guns from that make,
    model, caliber and year that are essentially
    identical. But where is the expert that ever states
    such caveats?

    With DNA analysis, we used to hear that either a
    suspect was cleared because the markers didnt match,
    or that there was a 1 in 50,000 (or 1 in 10,000,000,
    etc.,) chance that this was indeed the guilty person.
    Of course this also meant that, however remote, a
    certain number of other individuals would also match
    the DNA evidence. But we dont hear such things from
    the ballistics experts.

    But has anyone actually come across information to
    validate these shortcomings? If so, please let me

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             Date: Tue, 05 Aug 2003 06:14:52 +0100
             From: kotlas@email.unc.edu
             Subject: CIT Infobits -- july 2003

    CIT INFOBITS July 2003 No. 61 ISSN 1521-9275

    About INFOBITS

    INFOBITS is an electronic service of The University of North Carolina
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    CIT's Information Resources Consultant monitors and selects from a
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    U.S. Distance Education Survey
    Distance Learning Resources
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    Commercial vs. Research Library Online Reference Services
    Perennial Plagiarism
    Spam Wars
    Recommended Reading

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