Phil 6334 class material

Induction, Popper and Pseudoscience

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February is a good time to read or reread these pages from Popper’s Conjectures and Refutations. Below are (a) some of my newer reflections on Popper after rereading him in the graduate seminar I taught one year ago with Aris Spanos (Phil 6334), and (b) my slides on Popper and the philosophical problem of induction, first posted here. I welcome reader questions on either.

As is typical in rereading any deep philosopher, I discover (or rediscover) different morsels of clues to understanding—whether fully intended by the philosopher or a byproduct of their other insights, and a more contemporary reading. So it is with Popper. A couple of key ideas to emerge from the seminar discussion (my slides are below) are:

    1. Unlike the “naïve” empiricists of the day, Popper recognized that observations are not just given unproblematically, but also require an interpretation, an interest, a point of view, a problem. What came first, a hypothesis or an observation? Another hypothesis, if only at a lower level, says Popper.  He draws the contrast with Wittgenstein’s “verificationism”. In typical positivist style, the verificationist sees observations as the given “atoms,” and other knowledge is built up out of truth functional operations on those atoms.[1] However, scientific generalizations beyond the given observations cannot be so deduced, hence the traditional philosophical problem of induction isn’t solvable. One is left trying to build a formal “inductive logic” (generally deductive affairs, ironically) that is thought to capture intuitions about scientific inference (a largely degenerating program). The formal probabilists, as well as philosophical Bayesianism, may be seen as descendants of the logical positivists–instrumentalists, verificationists, operationalists (and the corresponding “isms”). So understanding Popper throws a great deal of light on current day philosophy of probability and statistics.

Continue reading

Categories: Phil 6334 class material, Popper, Statistics

You can only become coherent by ‘converting’ non-Bayesianly

Mayo looks at Bayesian foundations

“What ever happened to Bayesian foundations?” was one of the final topics of our seminar (Mayo/SpanosPhil6334). In the past 15 years or so, not only have (some? most?) Bayesians come to accept violations of the Likelihood Principle, they have also tended to disown Dutch Book arguments, and the very idea of inductive inference as updating beliefs by Bayesian conditionalization has evanescencd. In one of Thursday’s readings, by Baccus, Kyburg, and Thalos (1990)[1], it is argued that under certain conditions, it is never a rational course of action to change belief by Bayesian conditionalization. Here’s a short snippet for your Saturday night reading (the full paper is https://errorstatistics.files.wordpress.com/2014/05/bacchus_kyburg_thalos-against-conditionalization.pdf): Continue reading

Categories: Bayes' Theorem, Phil 6334 class material, Statistics | Tags: ,

Phil 6334: Notes on Bayesian Inference: Day #11 Slides

 

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A. Spanos Probability/Statistics Lecture Notes 7: An Introduction to Bayesian Inference (4/10/14)

Categories: Bayesian/frequentist, Phil 6334 class material, Statistics

Phil 6334: March 26, philosophy of misspecification testing (Day #9 slides)

 

may-4-8-aris-spanos-e2809contology-methodology-in-statistical-modelinge2809d“Probability/Statistics Lecture Notes 6: An Introduction to Mis-Specification (M-S) Testing” (Aris Spanos)

 

[Other slides from Day 9 by guest, John Byrd, can be found here.]

Categories: misspecification testing, Phil 6334 class material, Spanos, Statistics

Significance tests and frequentist principles of evidence: Phil6334 Day #6

picture-216-1Slides (2 sets) from Phil 6334 2/27/14 class (Day#6).

spanos

D. Mayo:
“Frequentist Statistics as a Theory of Inductive Inference”

A. Spanos
“Probability/Statistics Lecture Notes 4: Hypothesis Testing”

Categories: P-values, Phil 6334 class material, Philosophy of Statistics, Statistics | Tags:

Phil6334: Feb 24, 2014: Induction, Popper and pseudoscience (Day #4)

Phil 6334* Day #4: Mayo slides follow the comments below. (Make-up for Feb 13 snow day.) Popper reading is from Conjectures and Refutations.

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As is typical in rereading any deep philosopher, I discover (or rediscover) different morsals of clues to understanding—whether fully intended by the philosopher or a byproduct of their other insights, and a more contemporary reading. So it is with Popper. A couple of key ideas to emerge from Monday’s (make-up) class and the seminar discussion (my slides are below):

  1. Unlike the “naïve” empiricists of the day, Popper recognized that observations are not just given unproblematically, but also require an interpretation, an interest, a point of view, a problem. What came first, a hypothesis or an observation? Another hypothesis, if only at a lower level, says Popper.  He draws the contrast with Wittgenstein’s “verificationism”. In typical positivist style, the verificationist sees observations as the given “atoms,” and other knowledge is built up out of truth functional operations on those atoms.[1] However, scientific generalizations beyond the given observations cannot be so deduced, hence the traditional philosophical problem of induction isn’t solvable. One is left trying to build a formal “inductive logic” (generally deductive affairs, ironically) that is thought to capture intuitions about scientific inference (a largely degenerating program). The formal probabilists, as well as philosophical Bayesianism, may be seen as descendants of the logical positivists–instrumentalists, verificationists, operationalists (and the corresponding “isms”). So understanding Popper throws a lot of light on current day philosophy of probability and statistics.
  2. The fact that observations must be interpreted opens the door to interpretations that prejudge the construal of data. With enough interpretive latitude, anything (or practically anything) that is observed can be interpreted as in sync with a general claim H. (Once you opened your eyes, you see confirmations everywhere, as with a gestalt conversion, as Popper put it.) For Popper, positive instances of a general claim H, i.e., observations that agree with or “fit” H, do not even count as evidence for H if virtually any result could be interpreted as according with H.
    Note a modification of Popper here: Instead of putting the “riskiness” on H itself, it is the method of assessment or testing that bears the burden of showing that something (ideally quite a lot) has been done in order to scrutinize the way the data were interpreted (to avoid “verification bias”). The scrutiny needs to ensure that it would be difficult (rather than easy) to get an accordance between data x and H (as strong as the one obtained) if H were false (or specifiably flawed). Continue reading
Categories: Phil 6334 class material, Popper, Statistics

Phil 6334: Day #3: Feb 6, 2014

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Day #3: Spanos lecture notes 2, and reading/resources from Feb 6 seminar 

6334 Day 3 slides: Spanos-lecture-2

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Crupi & Tentori (2010). Irrelevant Conjunction: Statement and Solution of a New Paradox, Phil Sci, 77, 1–13.

Hawthorne & Fitelson (2004). Re-Solving Irrelevant Conjunction with Probabilistic Independence, Phil Sci 71: 505–514.

Skryms (1975) Choice and Chance 2nd ed. Chapter V and Carnap (pp. 206-211), Dickerson Pub. Co.

Mayo posts on the tacking paradox: Oct. 25, 2013: “Bayesian Confirmation Philosophy and the Tacking Paradox (iv)*” &  Oct 25.

An update on this issue will appear shortly in a separate blogpost.

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READING FOR NEXT WEEK
Selection (pp. 35-59) from: Popper (1962). Conjectures and RefutationsThe Growth of Scientific Knowledge. Basic Books. 

Categories: Bayes' Theorem, Phil 6334 class material, Statistics

Phil 6334: Day #2 Slides

 

Picture 216 1mayo Day #2, Part 1: D. Mayo: 

Class, Part 2: A. Spanos:picture-072-1-1
Probability/Statistics Lecture Notes 1: Introduction to Probability and Statistical Inference

Day #1 slides are here.

Categories: Phil 6334 class material, Philosophy of Statistics, Statistics

Phil 6334: Slides from Day #1: Four Waves in Philosophy of Statistics

images-4First installment 6334 syllabus (Mayo and Spanos)
D. Mayo slides from Day #1: Jan 23, 2014

 

I will post seminar slides here (they will generally be ragtag affairs), links to the papers are in the syllabus.

Categories: Phil 6334 class material, Philosophy of Statistics, Statistics

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