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Monday, May 20, 2019

Define "evidence"

Ahhh... "Just the facts." 

My (non-dictionary) definition:
EVIDENCE: Information which renders a true conclusion more likely, or (much more rarely), constitutes proof of a true conclusion (a.k.a. "dispositive evidence").
Anyone see anything at least episodically problematic there? Say tuned. Lots to unpack in this upcoming post. Let's just say for openers I'm a bit of a pedantic stickler for precise definitions as a starting point for rational and productive discourse (e.g., "Deliberation Science," anyone?).

It behooves us to all be singing from the same sheet of music.

1. The available body of facts or information indicating whether a belief or proposition is true or valid. ‘the study finds little evidence of overt discrimination’

1.1 (Law) Information drawn from personal testimony, a document, or a material object, used to establish facts in a legal investigation or admissible as testimony in a law court. ‘without evidence, they can't bring a charge’

1.2 Signs or indications of something. ‘there was no obvious evidence of a break-in’
BTW, apropos of 1.1, my trusty Black's Law Dictionary (10th ed.) devotes five pages [pp 576-581] to the word "evidence" and its related phrases and usages (most of them obviously pertaining to the legal domain).
"Information which renders a true conclusion more likely..." The briefest reflection extends that definition to sensory organ initiated perceptions. Is that rustling in the bushes outside your tent that of a bear? Does that acute smell of gas portend an incipient explosion? Is that "sound of 100 approaching freight trains" evidence of a tornado headed your way? Is that mole cancerous? etc.
In terms of human "arguments," any assertive premise statement ("truth claim") that fails to improve the likelihood of a true conclusion is at best simply rhetorical noise, and at worst a rhetorical fallacy. We have too much of it in our discourse.

A recent article in my AAAS Science Magazine made me aware of this:
H. R. 4174, ‘‘Foundations for Evidence-Based Policymaking Act of 2018’’—01/14/2019, Public Law No: 115-435.
"There is no natural constituency for evidence-based policy. It should, by rights, be the public who wants the most from their government (and their public funds). But the public, like most politicians, is often not aware of the ins and outs of evaluation methods and evidence. Think tanks and academics have long filled this gap and will likely continue to play key roles. But legislation signed into law in early 2019 could transform the way U.S. government officials design programs by introducing more scientific evidence into the process…"
Really? Under a Donald Trump administration? How did that happen? He signed the final bill. We can rest assured he carefully read every word of its 29 pages.

‘‘§ 311. Definitions
‘‘In this subchapter:

‘‘(3) EVALUATION.—The term ‘evaluation’ means an assessment using systematic data collection and analysis of one or more programs, policies, and organizations intended to assess their effectiveness and efficiency.
‘‘(4) EVIDENCE.—The term ‘evidence’ has the meaning given that term in section 3561 of title 44.

The term “evidence” means information produced as a result of statistical activities conducted for a statistical purpose.

(10)Statistical activities.—The term “statistical activities”—
(A) means the collection, compilation, processing, or analysis of data for the purpose of describing or making estimates concerning the whole, or relevant groups or components within, the economy, society, or the natural environment; and
(B) includes the development of methods or resources that support those activities, such as measurement methods, models, statistical classifications, or sampling frames.

(12)Statistical purpose.—The term “statistical purpose”—
(A) means the description, estimation, or analysis of the characteristics of groups, without identifying the individuals or organizations that comprise such groups; and
(B) includes the development, implementation, or maintenance of methods, technical or administrative procedures, or information resources that support the purposes described in subparagraph (A)...
Well, isn't that interesting? Enter "Data Science," anyone?
A couple of passing thoughts on evaluative classification of empirical "evidence." In conventional usage, we often resort to qualitative ordinal ranking, with evidence strength thought of as ranging from "dispositive" to "nll," with (descendingly) "extremely strong," "strong," "moderate," "weak," "extremely weak" designations in between. Sometimes we gussy things up by stating nominally "quantitative" evidentiary "probabilities" when, properly, to cite just one caveat, we should be proffering what are really "probability estimates." The potential problems with inferential statistics bloom exponentially from there. See, e.g., my 1998 thesis rant on drug testing lab stats naivete.
UPDATE: just in, of relevance,
EPA Changes Math to Allow Burning of More Coal


"Evidence-Based Medicine." Not universally loved, historically. Still often dissed as anti-innovation "cookbook medicine" by apologists for "Eminence-Based Medicine."
"[S]ince antiquity, the mark of distinction of a learned man had been the certainty of his knowledge. A doctor knew—he did not need to test his kind of knowledge empirically because this would imply acknowledgement of uncertainty."—Ulrich Tröhler

Are they?

The Neurologica Blog asks "How do we know?"
"...Science itself is not a set of “facts” but a method of exploration. It starts from specific premises, and it doesn’t even hold that these premises are Truth, just that they are necessary for science to function. We call these premises methodological naturalism – every material effect has a material cause, and there is no magic or miracles (arbitrary suspensions of the laws of nature). At least you cannot invoke such miracles when making an argument. Based on this premise, science uses logic and observation not to prove things correct, but to prove things wrong. (That is a key point – you can never prove something wrong if you can invoke miracles as needed.) By conducting experiments and making observations science can exclude hypotheses that are incompatible with the evidence. Whatever is left, the explanations that have survived dedicated attempts at proving them wrong, are then considered tentatively to be possible or even probable explanations. The longer a scientific notion survives, and the more independent lines of evidence that lead us to the same conclusion, the higher our confidence in that idea..."
"At a time rife with a disregard for facts and the methods used to produce them (even when they portend a catastrophic future), perhaps [C.P.] Snow, were he alive today, would encourage scientists and humanists, engineers and artists, to focus on the one culture to which we all  belong."
In May 1959, Charles Percy Snow took the stage at the Senate House in Cambridge to give the annual Rede lecture. The British chemist-turned-novelist’s appearance—a rotund jowly face atop a bulky, shambling figure—led wags to comment that the speaker was well rounded in more than just his intellect.

Snow’s talk, titled “The Two Cultures and the Scientific Revolution,” broadly diagnosed a problem he believed challenged the future of all western democracies. For years, he had noted that British humanists and scientists shared “little but different kinds of incomprehension and dislike” (1, 2). The inability of literary scholars and scientists to understand and communicate with one another was not just an intellectual loss, Snow claimed, but something that threatened the ability of modern states to address the world’s problems...
Great, extensive, timely review I ordered the book. Only six bucks in paperback.


This was cited in the notes of the Science Magazine article:

Downloaded it, read it in short order. Excellent.
The Cold War was a time when psychology came into its own as a tool of social analysis. With marked rapidity the structural, institutional, and economic ways of understanding American society that had dominated academic and public discourse in preceding decades gave way to explanations framed in terms of the psyche…

If psychology could explain everything, there was one aspect of the self that held special importance to the intellectual and policy worlds: open-mindedness. Open-mindedness was a kind of mind characterized by autonomy, creativity, and the use of reason. To the scientific experts, intellectuals, and policy makers who developed and utilized the concept of the open mind, this type of self served simultaneously as model and ideal of national and intellectual character. They projected upon the open mind their aspirations for the American character and liberal pluralist democracy, for scientific thinking and true intellectual inquiry. Indeed, for some of these individuals the open mind transcended the academic and political, as its traits were even conscripted to serve as criteria for human nature itself.

Cold War intellectuals and policy makers saw in open-mindedness solutions to the most pressing problems faced by the nation. Those who defined American foreign policy believed that open-minded autonomy, a hallmark of American virtue, posed a threat to the communist system. Traditional or authoritarian societies could not be sustained in the presence of a citizen body that thought autonomously, but for a modern democracy like America, open-mindedness would have the opposite effect, offering social cohesion. The open mind meant a respect for individuality, tolerance of difference, appreciation of pluralism, and appreciation of freedom of thought. If citizens were sufficiently equipped with these virtues, thought policy makers and social critics, the nation would flourish…

Cohen-Cole, Jamie. The Open Mind (pp. 1-2). University of Chicago Press. Kindle Edition.
I wrote an Amazon review.
I emailed the author: "You are one damn fine scholar." A compelling tour through my 73 years (and my many years working in science / engineering / tech domains) and the decades that preceded them. "Open-mindedness" has hit a serious rough patch in recent years--in particular in the turbulent wake of the last Presidential election. We are coming upon a time when it may well soon be ruled at the highest level that behaviors grounded in "open-mindedness" violate some peoples' Constitutionally-protected "religious freedom," and that, reciprocally, behaviors stemming from irrational, close-minded prejudice will be ruled as "Constitutionally-protected" on grounds of "religious freedom." (Not just "opinions," actions.)

You want a good historical understanding of how we got here, read this book. Beyond its erudition and cogent observations, I found it a FUN read.

More to come...

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