i

Dec. 12th, 2016 08:57 am
jsburbidge: (Cottage)
For about the 100th time I have been reading a book of science popularization when it stops dead to explain the imaginary and complex numbers from scratch.

It's been almost 250 years since Euler's Elements of Algebra. Maybe it's time to introduce C and a complete coverage of the number system as part of a basic mathematical education in elementary school?

Power laws

Nov. 12th, 2014 11:33 am
jsburbidge: (Cottage)
It is starting to look as though one of the basic elements of functional internet literacy is awareness of power law distributions.

These show up frequently in social patterns involving either markets with immiscible goods or social networks of any significant size, and the Internet frequently involves the intersection of both. (The "Long Tail" of Chris Anderson's book title refers to the low end of a power law distribution, for example.)

People who point to a few highly successful self-published authors on Amazon as evidence that self-publishing is a gateway to success are ignoring the realities of a power-law distribution, much as people who pointed to weblogs as a way to get a voice out were a decade ago when blogging was new.

What caught my attention this morning regarding this was a segment on Metro Morning regarding a study involving teens and their use of social media. The study itself was done by a group at Centennial College and I have no doubt that certain aspects of it -- pointing out a relatively widespread willingness to ignore privacy concerns when posting to social networks, for example, or identifying hashtags related to self-promotion on twitter -- are at least grounded in real research. (On the other hand, their methodology page does not fill me with a great deal of confidence in their rigor, relating at least three "exploratory" (I assume = "focus") groups and "hundreds – possibly thousands - of hours combing social media sites, watching GIFs, decoding hashtags and generally documenting the trajectories of young people’s social identity exploration". I see no signs of mathematical rigor.)

But when I heard the author -- Debbie Gordon -- talk about some teens having hundreds of thousands or millions of followers, my immediate reaction was: "that has to be a power-law effect" -- popularity figures in a network environment are always power laws unless there's some significant constraint on them. Tails drop off rapidly in a power law distribution, and citing a few high figures does not provide a representative study.

(Even citing averages is misleading. I took the most-recently added ninety books on my LibraryThing account and then graphed them by number of members listing them. These formed a classic power curve, with a maximum value of 12,553, a minimum of 1, and an arithmetic mean of 822.833. However, 72 of the 90 books fell below the arithmetic mean, 54 were below half the mean (411), and the median was 199.5. 30 fell below 100.)

The numeric citations moved the interview from a "vaguely interesting" category into a "this is another one of those alarmist stories about how youth are going to hell in a handbasket that I've been hearing ever since I was young (when the stories bore no relation to anyone I knew)".

There have been a number of interesting discussions about how the young are adjusting to living in a panopticon society and how their values on privacy are not those of older generations. (Well, older living generations; the thegns of an Anglo-Saxon hall also had different privacy expectations, as did the inhabitants of a 16th century village.) This does not sound like a serious contribution to that discussion.
jsburbidge: (Cottage)
The Ontario Government is getting into a frazzle about the failure rate of public school students in mathematics, offering bonuses for teachers doing skills upgrading.  Fingers have been pointed at the teachers' math skills, their math teaching skills, the curriculum, and other possible culprits.

There is, of course, a long-term issue with teachers and math skills, in that someone with good math skills coming out of university can find more attractive areas to specialize in than teaching.

However, I have spent the past several years watching my daughter deal with the curriculum, and I do think that there is a problem with it: it fits the needs of almost no children. It flits from topic to topic in such a way that students who have difficulty do not get enough drill to master the issues; but it also allows for no real exploration of the issues by students who are good at math, for the same reason.

They will have a two or three week unit on series, for example, which could be extended to any number of interesting things to explore; but then there will be a sharp break and they'll move on to an equally short unit on, say, geometry.

And while we're on the topic of math skills in the general population, maybe we should ask: what skills?

A few weeks ago I was on public transit and saw an ad designed to popularize the idea of a need for math skills. The example problem it gave was a simple word problem of the sort which requires conversion from words to a simple polynomial and then solving for x. It was soluble by someone with high-school math trivially. But I thought: for someone who does not work in the sciences or engineering, where is that type of skill necessary?  Certainly not in everyday life; nor, I think, in accountancy or other similar fields, where numbers tend to be delivered and manipulated in quite a different way. So for a student with an interest in (say) history and languages, there's no obvious reason for this sort of skill to be considered a critical one: yet the provincial curriculum makes it important. In contrast, estimating probabilities and risk in a back-of-the-envelope manner is probably more important in day-to-day life; humans are notoriously bad at it. Understanding some of the underlying issues around encryption (such as the difficulty of factoring large primes, or the ease of doing frequency analysis) is becoming a generally useful skill set (not the ability to do it, but the understanding of what is hard and what is easy).

Students who have the potential to be good scientists, mathematicians, engineers, and the like need a far more challenging, ambitious, and interesting curriculum than we are giving them. (A genuinely competent 17-year-old should be able to handle Hardy's Course of Pure Mathematics if properly prepared.) Students who are not going there need only a fraction of what we are shoving down their throats. (When was the last time I really needed, say, trigonometry at the high-school level? I don't have to measure very many things by angle-and-one-side mechanisms; either I need more -- Fourier analysis, full-blown trigonometric functions, etc., or I need none.) And the relatively rare students who have the ability but are interested in everything -- literature, history, philosophy, and languages as well as maths and sciences -- can handle the more difficult stream and benefit from it.

Profile

jsburbidge: (Default)
jsburbidge

April 2025

S M T W T F S
  12345
67 89101112
13141516171819
20212223242526
27282930   

Syndicate

RSS Atom

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated May. 22nd, 2025 06:04 am
Powered by Dreamwidth Studios