Posted by: Alexandre Borovik | October 20, 2017

Handwriting and “Cortical homunculus”

Правописание – это то, что в старой России в курсе физиологии развития детей (стандартный курс был в пединститутах – интересно, остался?) называлось “мелкая моторика” (видимо, по английски это dexterity). Не знаю, что сейчас говорит наука, но тогда считалось, что в человеском мозгу центры речи близко связаны с центрами, контролиующими движение рук – в частности, отсюда происходит неконтролиуемая жестикуляция во время разговора.Рука – это громадная часть коры головного мозга, как показано на классической картинке Cortical homunculus.

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Posted by: Alexandre Borovik | October 19, 2017

“If on a Winter’s Night a Traveller”

The title of Italo Calvino‘s book is great. When I first time saw the book on a shop shelf, I bought it on impulse because on its title. To the Russian year, it has immediate connotations with the famous passage from Chekhov’s “Ionych”:

Then they all sat down in the drawing-room with very serious faces, and Vera Iosifovna read her novel. It began like this: “The frost was intense… .” The windows were wide open; from the kitchen came the clatter of knives and the smell of fried onions… . It was comfortable in the soft deep arm-chair; the lights had such a friendly twinkle in the twilight of the drawing-room, and at the moment on a summer evening when sounds of voices and laughter floated in from the street and whiffs of lilac from the yard, it was difficult to grasp that the frost was intense, and that the setting sun was lighting with its chilly rays a solitary wayfarer on the snowy plain. Vera Iosifovna read how a beautiful young countess founded a school, a hospital, a library, in her village, and fell in love with a wandering artist; she read of what never happens in real life, and yet it was pleasant to listen — it was comfortable, and such agreeable, serene thoughts kept coming into the mind, one had no desire to get up.

In Russia in “the period of stagnation”, the expression “The frost was intense” (“мороз крепчал”) became proverbial and was transformed into a less politically correct, but more politically charged, derivative.

And I was delighted to discover that my instinctive choice was correct and that, indeed, Calvino’s book “did exactly what it said on the tin”!

Posted by: Alexandre Borovik | September 28, 2017

“Mirrors and reflections” in Japanese

Alexandre V. Borovik and Anna Borovik, “Mirrors and Reflections: The Geometry of Finite Reflection Groups

Posted by: Alexandre Borovik | August 17, 2017

Evaluating students’ evaluations of professors

This paper contains some bizarre observations:
Michela Braga, Marco Paccagnella, Michele Pellizzari, Evaluating students’ evaluations of professors. Economics of Education Review 41 (214) 71-88.
Abstract: This paper contrasts measures of teacher effectiveness with the students’ evaluations for
the same teachers using administrative data from Bocconi University. The effectiveness
measures are estimated by comparing the performance in follow-on coursework of
students who are randomly assigned to teachers. We find that teacher quality matters
substantially and that our measure of effectiveness is negatively correlated with the
students’ evaluations of professors. A simple theory rationalizes this result under the
assumption that students evaluate professors based on their realized utility, an
assumption that is supported by additional evidence that the evaluations respond to
meteorological conditions.

An interesting paper:

Bob Uttl, Carmela A.White, Daniela Wong Gonzalez, Meta-analysis of faculty’s teaching effectiveness:  Student evaluation of teaching ratings and student learning are not related. Studies in Educational Evaluation, Volume 54, September 2017, Pages 22-42.

Abstract: Student evaluation of teaching (SET) ratings are used to evaluate faculty’s teaching effectiveness based on a widespread belief that students learn more from highly rated professors. The key evidence cited in support of this belief are meta-analyses of multisection studies showing small-to-moderate correlations between SET ratings and student achievement (e.g., Cohen, 1980, 1981; Feldman, 1989). We re-analyzed previously published meta-analyses of the multisection studies and found that their findings were an artifact of small sample sized studies and publication bias. Whereas the small sample sized studies showed large and moderate correlation, the
large sample sized studies showed no or only minimal correlation between SET ratings and learning. Our up-to-date meta-analysis of all multisection studies revealed no significant correlations between the SET ratings and learning. These findings suggest that institutions focused on student learning and career success may want to abandon SET ratings as a measure of faculty’s teaching effectiveness.

title = "Meta-analysis of faculty's teaching effectiveness: Student evaluation of teaching ratings and student learning are not related",
journal = "Studies in Educational Evaluation",
volume = "54",
number = "",
pages = "22 - 42",
year = "2017",
note = "Evaluation of teaching: Challenges and promises",
issn = "0191-491X",
doi = "",
url = "",
author = "Bob Uttl and Carmela A. White and Daniela Wong Gonzalez",
keywords = "Meta-analysis of student evaluation of teaching",
keywords = "Multisection studies",
keywords = "Validity",
keywords = "Teaching effectiveness",
keywords = "Evaluation of faculty",
keywords = "SET and learning correlations"

A press release from Mathematics in Open Access for Journal of Algebraic Combinatorics (2017-07-27) (see also a comment from Tim Gowers):

At the end of June 2017, the four editors-in-chief of the Journal of Algebraic Combinatorics informed Springer that they will not renew their contracts, which terminate on 31 December 2017. Nearly all of the editorial board members will also resign, to form the editorial board of a new journal that will be called Algebraic Combinatorics, run according to Fair Open Access Principles. The new journal Algebraic Combinatorics will be up and running very shortly, with interim editors-in-chief Satoshi Murai and Vic Reiner. The transition to Fair Open Access is supported by the organisation Mathematics in Open Access (MathOA). The editors of the Journal of Algebraic Combinatorics are Akihiro Munemasa, Christos Athanasiadis, Hugh Thomas and Hendrik van Maldeghem. Once their contracts with Springer expire, they will become editors-in-chief at Algebraic Combinatorics.

Why now? ‘There wasn’t a particular crisis. It has been becoming more and more clear that commercial journal publishers are charging high subscription fees and high Article Processing Charges (APCs), profiting from the volunteer labour of the academic community, and adding little value. It is getting easier and easier to automate the things that they once took care of. The actual printing and distribution of paper copies is also much less important than it has been in the past; this is something which we have decided we can do without’, says Hugh Thomas.

We were inspired by the Linguistics in Open Access (LingOA) project that flipped 4 journals in linguistics last year. We therefore also started a foundation Mathematics in Open Access (MathOA), that will help other journals in mathematics flip to Fair Open Access’ says Mark Wilson, one of the founding members of MathOA.


Posted by: Alexandre Borovik | July 19, 2017

Matrix Algebra

Lectures on Matrix Algebra, last update 19 July 2017, 09:56.

Posted by: Alexandre Borovik | March 30, 2017

Two elementary problems

Sketch the curve given by parametric equations

(a) \(x =\cos^2 t, \; y = \sin^2 t\)

(b) \(x = e^t, \; y = e^2t\)

Posted by: Alexandre Borovik | December 28, 2016

Immorality of forcing choice on others

I very much hope that this story is a hoax, I tried to locate the source on the Internet, but failed.

If it is not a hoax, then it is a huge breach of profession norms- made in a hurry and under stress, but still a breach. One should not put children in the situation of choice almost impossible for them -teachers should remember that. Actually, it is not a good idea to force moral  choice on people. In most  cases, it is immoral to force moral choice on others.

Posted by: Alexandre Borovik | December 28, 2016

Georgio de Chirico, “Mathematicians”

Georgio de Chirico, “Mathematicians”

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