Khan’s Video Lectures on Acceleration and Newton’s Second Law

Stimulated by “Re: Khan Academy on Sixty Minutes” [Hake (2012)], I went into the Khan Academy http://www.khanacademy.org/ and looked at two videos:

1. “Acceleration” at http://bit.ly/wycpxX, and

2. “Newton's Second Law” at http://bit.ly/xqoW4X.

These consist of Khan’s blackboard solutions of algorithmic exercises to find:

(1) the acceleration “a” of a Porsche, given the change in its velocity “v” during a change in time “t”; and

(2) the acceleration “a” of a block, given its mass “m” and the force “F” acting on the block.

There’s little attempt to lead students to a conceptual understanding of either acceleration or Newton's Second Law. There’s no emphasis on operational definitions of “velocity,” “time,” “acceleration,” “force,” or “mass.”

Khan appears to be (a) oblivious of physics education research, and (b) simply repeating in a traditional way the cookbook stuff he learned at MIT in passive-student lectures.

I note that there’s a 68-post thread “Khan Academy: Math instruction goes viral” on the MathEdCC at http://bit.ly/FO8Xll which contains, among other things, negative comments on Khan’s math video on averages at http://bit.ly/AaMkpu.

For example:

a. Guy Brandenburg (2011) wrote: “That is one of the worst lessons on stats and averages I have ever seen. . . . He acts like the important part is the computation itself. He gives no reason WHY we should add the numbers up then divide. . . . . . And people pay him money? And think he's doing a great job?. . . . He's about as bad as John Saxon.”

b. Domenico Rosa (2011) wrote: “I have not seen many of Khan’s videos, and his style of teaching is significantly inferior to the teachers that I had in the public school system in the factory city of Everett, MA. My point is this: All the hits that his videos are getting are indicative of the hunger for direct instruction -- a fact that has been completely missed by the media pundits who have been giving him so much exposure.”


Richard Hake, Emeritus Professor of Physics, Indiana University
Honorary Member, Curmudgeon Lodge of Deventer, The Netherlands
President, PEdants for Definitive Academic References
which Recognize the Invention of the Internet (PEDARRII)
rrhake@earthlink.net
Links to Articles: http://bit.ly/a6M5y0
Links to SDI Labs: http://bit.ly/9nGd3M
Blog: http://bit.ly/9yGsXh
Academia: http://iub.academia.edu/RichardHake
Twitter https://twitter.com/#!/rrhake

“I point to the following unwelcome truth: much as we might dislike the implications, research is showing that didactic exposition of abstract ideas and lines of reasoning (however engaging and lucid we might try to make them) to passive listeners yields pathetically thin results in learning and understanding - except in the very small percentage of students who are specially gifted in the field.”
Arnold Arons in Teaching Introductory Physics (p. vii, 1997)


REFERENCES [URL’s shortened by http://bit.ly/ and accessed on 16 March 2012.]
Arons, A.B. 1997. Teaching Introductory Physics. Wiley, publisher's information at http://bit.ly/jBcyBU. Amazon.com information at http://amzn.to/bBPfop. Note the searchable “Look Inside” feature.

Brandenburg, G. 2012. “Re: Khan Academy: Math instruction goes viral,” on the OPEN! MathEdCC archives at http://bit.ly/FOpC53. Post of 7 Sep 11:01 PM to MathEdCC. (The Math Forum fails to specify the time zone.)

Hake, R.R. 2012. “Re: Khan Academy on Sixty Minutes” on the OPEN! AERA-L archives at http://bit.ly/zsYxUk. Post of 15 Mar 2012 10:59:14-0700 to AERA-L and Net-Gold. The abstract and link to the complete post are being transmitted to several discussion lists and are also on my blog “Hake’sEdStuff”" at http://bit.ly/yapt2S with a provision for comments. I apologize for the several misspellings of "Khan" as "Kahn." It was all the fault of my spiel chequer - see e.g., Zar (1994, 2000).

Rosa, D. 2011. “Re: Khan Academy: Math instruction goes viral,” on the OPEN! MathEdCC archives at http://bit.ly/z2qEml. Post of 12 Sep 1:59 PM to MathEdCC. (The Math Forum fails to specify the time zone.)

Zar, J. 1994. “Candidate for a Pullet Surprise,” Journal of Irreproducible Results, January/February, p. 13. Reprinted “by popular demand” in the Journal of Irreproducible Results 45(5/6), 2000, p. 20; online at http://bit.ly/uW8mM7.

How Much Value is Added at Elite Institutions - Response to Haim #2

Some blog followers might be interested in a recent post “How Much Value is Added at Elite Institutions - Response to Haim #2” [Hake (2011d)].

********************************************

ABSTRACT: In my post “How Much Value is Added at Elite Institutions?” [Hake (2011c)], I wrote:

“. . . . demonstrations that the less-than-stellar value-added assessments of Korsunsky's high school and Stuyvesant High School are inequitable would require meaningful value-added measures such as normalized average pre-to-posttest gains on valid and consistently reliable tests of higher-order learning. . .”

Math-Teach's “Haim” responded: “The problem is that you are not sure what you are measuring."

NONSENSE! In the case of Harvard, the higher-order learning consisted of conceptual understanding of Newtonian mechanics.

Haim continued: “First, parents and students seem to know something about Stuyvesant that educator assessments clearly fail to discern. . . . . Second . . . very many of Stuyvesant's students graduate at a very high level (certainly by comparison to most other high school graduates) of academic achievement. . . . the real problem is transparent. It is the ceiling effect. . . .City-wide and state-wide assessments are simply not designed for academic institutions.”

The above has nothing whatsoever to do with the theme of my post: “It is conceivable that if there were ‘Eric Mazurs’ or ‘John Belchers’ at Korsunsky's high-school and the Stuyvesant High School, scenarios similar to that at Harvard and MIT might occur. . . . . [[i.e., realization that students were not learning much from traditional passive-student lecture methods followed by a switch to interactive-engagement pedagogy.]]. . . . , even though all those institutions are regarded as ‘elite.’ ”

********************************************

To access the complete 18 kB post please click on http://bit.ly/gxUOAb .

Richard Hake, Emeritus Professor of Physics, Indiana University

Honorary Member, Curmudgeon Lodge of Deventer, The Netherlands

President, PEdants for Definitive Academic References which Recognize the Invention of the Internet (PEDARRII)

rrhake@earthlink.net

http://www.physics.indiana.edu/~hake

http://www.physics.indiana.edu/~sdi

http://HakesEdStuff.blogspot.com

http://iub.academia.edu/RichardHake

“Above all things we must be aware of what I will call ‘inert ideas’

- that is to say, ideas that are merely received into the mind

without being utilized, or tested, or thrown into fresh combinations.”

Alfred North Whitehead (1929, 1965) in The Aims of Education

REFERENCES [URL's shortened by http://bit.ly/ and accessed on 26 Jan 2011.]

Hake, R.R. 2011a. “The Ceiling Effect #2” online on the OPEN! AERA-L archives at http://bit.ly/hUnHZe. Post of 12 Jan 2011 16:19:49-0800 to AERA-L and Net-Gold. The abstract and link to the complete post are being transmitted to various discussion lists are also online on my blog “Hake'sEdStuff” at http://bit.ly/gLWr7W with a provision for comments.

Hake, R.R. 2011b. “Value-Added Inequities: Should Value-Added Measures Be Used to Evaluate Teachers?” online on the OPEN! AERA-L archives at http://bit.ly/fN1HmD. Post of 18 Jan 2011 15:34:47-0800 to AERA-L and Net-Gold. The abstract and link to the complete post are being transmitted to various discussion lists are also online on my blog “Hake'sEdStuff” at http://bit.ly/h23shQ with a provision for comments.

Hake, R.R. 2011c. “How Much Value is Added at Elite Institutions?” online on the OPEN! AERA-L archives at http://bit.ly/g25OHd. Post of 22 Jan 2011 14:50:14-0800 to AERA-L and Net-Gold. The abstract and link to the complete post are being transmitted to various discussion lists are also online on my blog “Hake'sEdStuff” at http://bit.ly/gnLPjH with a provision for comments.

Hake, R.R. 2011d. “How Much Value is Added at Elite Institutions – Response to Haim #2” online on the OPEN! AERA-L archives at http://bit.ly/gxUOAb. Post of 26 Jan 2011 16:14:36-0800 to AERA-L and Net-Gold. The abstract and link to the complete post are being transmitted to various discussion lists. See also the relevant previous posts Hake (2011a,b,c)].

Whitehead, A.N. 1967. Aims of Education and other essays. Free Press. Amazon.com information at http://amzn.to/fIUbXB. First published in 1929. Note the “Look Inside” feature.