Tag: Mathematica

MAV’s Mathematica Games

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July 18, 2020

9:31 am

6 Comments on MAV’s Mathematica Games

VCE

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I’ve already posted Sai kumar Murali krishan’s Mathematica-VCE article, and fleshed it out a little. Here, I’ll give some of the back story, including a statement from Vinculum‘s editor, Roger Walter, and ending with a summary and a list of questions I sent to the MAV regarding the reviewing of Sai’s article, and to which I never expect to receive an answer. Throughout, I was curious whether the MAV would, once again, act in a gratuitously censorious manner, or whether they would now be wiser and publish Sai’s article; impressively, they accomplished both.

Last year, Sai was a student in my Monash Extension class. (It is irrelevant but ironic that Mathematica was used in this class in a limited but intelligent manner, for computing powers of large matrices, row reduction and the like.) The class was small and friendly, and fun, at least for me. I knew Sai well, and it’ll come as no surprise that he did very well in my class, but I had no sense of Sai’s Mathematica superpowers until the year had ended. Then John Kermond, Sai’s Specialist teacher, suggested I talk to Sai about Mathematica in VCE. Sai and I emailed back and forth a bit, and it became clear Sai had a very interesting story to tell.

I encouraged Sai to write up his gaming of VCE with Mathematica, with the goal of publishing in MAV’s journal Vinculum. Given the MAV’s previous conduct and general obsequiousness towards VCAA, some may suspect that goal was foolish or deliberate possum-stirring. With hindsight, it may have been the former but it was in no sense the latter.

There were a number of strong reasons to aim for Sai to write for Vinculum. First and foremost, Vinculum is the main senior school mathematics journal read by Victorian teachers, and was thus the natural home for an article such as Sai’s. Secondly, although Sai will clearly go far and needs absolutely no assistance from me, I thought it would be very good for Sai to have such a publication on his CV. Thirdly, I respected and continue to respect Vinculum‘s editor, Roger Walter, and I trusted he would see the importance of Sai’s article and would work hard to publish it. Finally, given the MAV had acted censoriously in the past and had been publicly called on it, I expected the MAV to be more circumspect in considering Sai’s article. On this last point, I was very wrong. Which is why we’re here now.

Sai quickly put together a very good draft, which I helped Sai tighten and polish. And, amusingly, I got Sai to tone down his language; Sai’s contempt for VCAA’s Mathematica crusade is significantly stronger than is indicated by the published article. Unfortunately, giving a clearer focus to Sai’s article also meant cutting out some very good material, on other clumsy and silly aspects of Mathematica in VCE. In particular, Sai put a lot of work into critiquing the sample Mathematica solutions provided by the VCAA, aspects of which Sai variously described, with supporting argument, as “contrived”, “incomplete”, “silly”, “bloated”, “obnoxious”, “abysmal” and “ludicrous”. (If he didn’t have better things to do, I’d retire and let Sai take over the blog.) I’m hoping to have Sai write a guest post on these solutions, and on other aspects of the Mathematica trial, in the near future.

In February, with a solid draft in hand, Sai submitted his article to Roger Walter, Vinculum‘s editor; I stayed in the loop, for the obvious reasons. The back and forth with Roger was sensible, efficient and amicable. Then, however, the MAV Publications Committee kicked in. What follows is a statement from Roger Walter, followed by my letter to the MAV (Publications Committee and CEO and President); that letter, as well as asking a number of questions, outlines the reviewing process and the frustration that it entailed.

And, failing any response from the MAV, that will end the story. I have heard nothing to indicate that the MAV is anything but satisfied with the manner in which Sai’s article was reviewed, which, if true, I find astonishing.

 

Statement from the Editor of Vinculum, Roger Walter (13/7)

I was very insistent that Sai’s article be published in Vinculum. This was partly my desire to publish, as far as is possible, all material that contributors have spent time and effort to put together, and partly because I was pleased to see a contribution from a student resourced from his experiences at secondary school. However, the main reason I pushed for publication was that the article itself had merit. This was for two reasons. Firstly, it was true, i.e. it clearly and accurately described the situation. Secondly, it was, at least in my mind, relevant – to both secondary teachers and to those who are responsible for planning our curriculum.

To me, two important statements were made (among others). One was that Mathematica was extremely powerful: too powerful for VCE, in fact, as it meant that students could answer questions without understanding the mathematics involved – an understanding which would be important for their future studies. The other is that Mathematica, being so much more powerful than the CAS calculators used by the majority of students, has the potential to create a non-level playing field. It is important that both teachers and those responsible for our curriculum are aware of this, if they aren’t already.

One of the things I try to do as editor, particularly in the editorials I write, and the material that is published, is to make educators think about what they are doing in their classes. I hope that if nothing else, this article achieves that. Also, as editor, I need to be impartial, and publish according to relevance and reality, regardless of my personal opinions, and the opinions and policies of other organisations. This impartiality is not always easy, but is relevant in the case of this article, and many others.

 

Letter From Marty to the MAV (13/7)

Dear Publications Committee, I am writing to you in regard to the article Mathematica and the Potential Gaming of VCE, by Sai kumar Murali krishnan (cc-ed) and just now published in the Term 3 issue of Vinculum. 

By way of background, it was at my suggestion that Sai wrote his article and submitted it to Vinculum. I also consulted with Sai during what turned out to be the lengthy and erratic reviewing process. Now, with Sai’s interest and agreement, there are a number of questions I wish to ask about that reviewing process. I am willing to publish any response by the Publications Committee or the MAV on my blog. I will interpret a lack of reply by Friday, 17 July as a decision to not comment.

Kind Regards, Marty Ross

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

Sai initially submitted his article to Roger Walter, the editor of Vinculum, in mid-February of this year. After some back and forth, by early March Roger and Sai considered the article polished and ready for the Term 2 issue of Vinculum. The Publications Committee, however, objected. In late March the Publications Committee demanded that the following two paragraphs, the final paragraphs of Sai’s article, be cut:

To the extent VCAA is aware of these issues, there is reason to doubt that they are sufficiently aware, or at least sufficiently concerned. VCAA, after all, has created and continues to maintain this strange and uneven playing field. As further evidence, VCAA provides sample Mathematica solutions, and it is telling that these solutions are clumsy, uninventive and calculator-mimicking, suggesting a limited understanding of Mathematica’s capabilities. 

Whatever naivety may exist, I believe it is unlikely to last. Nothing precludes the marketing of Mathematica packages designed specifically for VCE testing and, if Mathematica becomes widely available in VCE, I believe this commercialisation is inevitable. Such a development would turn VCAA’s implementation of Mathematica, which is already very problematic, into an obvious farce. 

Q1. Was there any reason for these cuts, beyond members of the Publications Committee being “not happy with comments about the VCAA”? Does the Publications Committee generally regard such unhappiness as sufficient reason to censor an author? 

Q2. Given that the criticism of VCAA was objectively valid and directly relevant, and given the potential commercialisation of Mathematica in VCE is an obvious and significant concern, will the Publications Committee now acknowledge there was no editorial or policy reason for demanding these paragraphs be cut? If not, will the Publications Committee now, finally, state any such reason?

Reluctantly, Sai then accepted these unjustified cuts, together with a new conclusion, with the understanding that publication could go ahead in Term 2, and with no further requests for substantial changes. Almost immediately, however, the Publications Committee demanded this second version of Sai’s article be held over until the Term 3 issue of Vinculum. The reason given to Sai for this delay was the Publications Committee “wanted time to consider the rest of the article and the conclusion”.

Q3. Will the Publications Committee now acknowledge that demanding a substantial and unjustified cut, and then subsequently demanding further time for review was a flawed and unfair process? Will the Publications Committee now acknowledge that in these circumstances, and in any circumstances, such a demand for further time should be accompanied by clear and substantive reasons, reasons that were entirely absent in this instance? Will the Publications Committee now indicate what specific parts of the article needed to be considered further, and why?

In mid-April the Publications Committee contacted Sai about further revising the second version of his article. The Publication Committee failed to indicate, much less argue for, a single flaw in this version. Rather, the Publications Committee requested that Sai add to his article, that the article also indicate what teachers could do in “using calculators and technology to support rather than bypass technology [sic]”. To this end, the Publications Committee also indicated they had contacted an MAV consultant familiar with Mathematica “to help [Sai] complete the article”. 

Q4. Was the intent of the Publication Committee at that stage simply to dilute the clear content and message of Sai’s article? Will the Publications Committee now acknowledge that the suggested expansion of Sai’s article was unnecessary and unhelpful, at best orthogonal to the clear content and message of his article? Given this orthogonality and the absence of any claim of error in Sai’s article, will the Publications committee now acknowledge that at that stage they simply should have apologised to Sai for the needless delay and have accepted the second version of Sai’s article?

Q5. Does the Publication Committee understand the distinction between offering “help” and attempting to impose it, and will the Publications Committee now acknowledge the extraordinary presumptuousness of initiating “help” before having even canvassed the idea with Sai? Sai quickly replied to the Publications Committee, rejecting this proposal, and making it clear that his article should be accepted or rejected as is. Sai also clearly and carefully detailed the flaws and frustrations of the review process to that stage.

Q6. Why did the Publications Committee not respond to the concerns raised in Sai’s email? Why did the Publications Committee still decline to publish Sai’s article, still without providing a single reason beyond a vague and unjustified “too negative”?

Over Roger’s objections, the Publications Committee continued to refuse to publish the second version of Sai’s article. In an attempt to placate a member of the Publications Committee, Roger suggested “a possible insertion which … doesn’t need to be at the end”:

Technology, including Mathematica, calculators, spreadsheets and the many online programs, have tremendous potential to assist students with learning, understanding and applying mathematics. What is important for educators is to be careful that students are not using this technology to bypass learning and understanding mathematics.

Although Roger’s proposal was clearly well-intentioned, Sai considered, and considers, Roger’s paragraph to be clumsy, unnecessary and forced, particularly as a concluding paragraph. He also didn’t believe for a minute the inclusion of this paragraph would placate the objecting member.  Nonetheless, Sai was willing to consider it, and asked Roger: IF Sai agreed to this third version, with the original conclusion cut and this new conclusion properly incorporated, would that THEN be acceptable to the Publications Committee? Sai never received an answer.

Q7. Why did Sai never receive an answer to this question, on a proposal originating from discussion within the Publications Committee? Does the Publications Committee now acknowledge that this failure to respond was rude and unprofessional? In early May, Sai received the following communication from the Publications Committee:

The MAV are continuing internal discussions regarding the publication of the Mathematica article in alignment with MAV’s publication policy. It is expected that a decision may be provided by the end of Term 3.

Q8. Why, after months of failing to indicate a single flaw in Sai’s article, did the Publications Committee consciously and pointedly fail to tell Sai anything about any further “internal discussions”? What, precisely, in the “publication policy” necessitated that Sai was given no opportunity to comment on these “internal discussions” and, in particular, why was Sai given no opportunity to confirm or correct the version of his article then being considered? 

Sai responded, indicating his frustration with the further delay and lack of communication. The Publication Committee responded:

1. Mathematica article is not to be included in Term 3. Pending subcommittee decision, it will be published in Term 4.

2. MAV are ‘continuing internal discussions regarding the publication of the Mathematica article in alignment with MAV’s publication policy. It is expected that a decision may be provided by the end of Term 3”.

Q9. Why was there a loud and definitive, and subsequently false, statement that Sai’s article would be further delayed until Term 4? Why was this further delay left unexplained? 

Q10. Why did the Publications Committee not inform Sai of this “subcommittee” directly and immediately upon its formation? Who were the members on the subcommittee, what was the role of the subcommittee, and who determined this membership and role? On what formal basis and with what justification did the Publications Committee deprive Sai of this information?

Q11. Was the subcommittee properly informed that Sai had never agreed to Roger’s inserted paragraph being the conclusion to Sai’s article, and if not then why not? If, as appears to be the case, the subcommittee was not informed of this, will the Publication Committee now acknowledge that this lapse was a very serious error, and will the Publication Committee now apologise to Sai for this error?

Q12. What summary and/or advice and/or opinion did the Publications Committee provide to the subcommittee, and why did Sai not also receive any such material?  In particular, if the Publications Committee indicated substantive objections, after having failed for months to do so to Sai directly, why did the Publications Committee not then inform Sai of these objections? 

Finally, in early June, the Publications Committee presented Sai with a fourth version of his article, presumably the work of the “subcommittee”.  The Publications Committee indicated they had agreed to publish this fourth version in Vinculum. It was made clear that this version of the article, which still included Roger’s inserted paragraph as conclusion, was not open to any further discussion, and that Sai had to either accept or decline. It was also indicated that the “aim” was still to publish in Term 4. Given the changes from the third to the fourth version were few and very minor, and swallowing his annoyance with the demand to conclude with Roger’s paragraph, Sai quickly agreed to this fourth version of his article. 

Sai was relieved when, presumably due to the wise counsel of the subcommittee, the reviewing ordeal finally ended with an agreement to publish. He is also very pleased to see his article appear in the Term 3 issue of Vinculum. The article as published is identical to the fourth version, except for a new title and the inclusion of a clarifying footnote, both agreed upon without dispute. Which raises the final questions.

Q13. Given that the changes from the third version of Sai’s article to the fourth version were very few in number and were all very minor, does the Publications Committee accept that the decision of the “subcommittee” repudiates the months of secretive stonewalling of the Publications Committee?

Q14. Given there are only minor differences between the second, March, version of Sai’s article and the final, July, published version of Sai’s article, and given Sai was never presented with a single substantive criticism of his article, will the Publications Committee now acknowledge that this whole review process could have been handled in a significantly more efficient, more thoughtful, more open and more respectful manner

Q15. Will the Publications Committee now extend a formal apology to Sai?

How to Play VCE with Mathematica

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July 16, 2020

2:12 pm

11 Comments on How to Play VCE with Mathematica

VCE

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An article titled Mathematica and the Potential Gaming of VCE has just appeared in the MAV’s journal Vinculum (and we have posted it here). By Sai kumar Murali krishnan, who completed VCE last year and who we previously mentioned in this post, the article delivers what the title promises (noting the “Potential” is redundant): Sai demonstrates how Mathematica’s huge library of functions and extremely powerful programming can be used, and has been used, to trivialise VCE maths exams. We believe Sai’s article is very interesting and very important. (For anyone interested to do so, Sai can be contacted by email here.)

Also likely to be of interest, at least to readers of this blog, is the story of the long and weird battle to have Sai’s article appear. Roger Walter, Vinculum’s editor, deserves a hell of a lot of credit for seeing that battle through and ensuring Sai’s article survived, largely unscathed. And a disclaimer: we played a role in Sai choosing to write the article, and we were also involved in the subsequent battle. We intend to write on all of this in the near future.

With Sai’s permission, we’ve posted his article here. In this post we’ll give a few more examples and we’ll provide some concluding paragraphs, which didn’t make it into Sai’s published article. By way of background, Mathematica memory need not be cleared before taking an exam or SAC. Secondly, in computer-based (CBE) Methods, a student enters their answers directly into the Mathematica notebook; this means that Mathematica code and output in and of itself constitutes acceptable working, and is very close to sufficient as answer. 

First, here is a multiple choice question from the 2019 Mathematical Methods exam, which we also discussed here:

The problem is to determine Pr(X > 0). Here is Sai’s solution, utilising standard Mathematica functions:

The point is, of course, that the application of functions such as Area and Polygon requires very little sense of the mathematics involved. For an example requiring no mathematical sense whatsoever, consider the following multiple choice question, which appeared on the 2017 Mathematical Methods exam:

The question is of a standard type, and for these questions Sai created the Mathematica function FTest. The following is Sai’s complete Mathematica working to solve the question above:

A final example, again from the 2019 Mathematical Methods exam:

Here is Sai’s Mathematica working for this question, using two functions he created, FInfo and TangentLine:

Sai’s Vinculum paper contains a number of other examples, and Sai has created a huge library of incredibly sophisticated functions to tackle VCE questions, a library which he shared with his fellow VCE students. Sai’s work raises obvious issues, not least of which is the grossly unfair competition between the majority handheld-CAS students and the few Mathematica-powered students. The original version of Sai’s article ended with two paragraphs, which the MAV Publications Committee demanded be cut:

To the extent VCAA is aware of these issues, there is reason to doubt that they are sufficiently aware, or at least sufficiently concerned. VCAA, after all, has created and continues to maintain this strange and uneven playing field. As further evidence, VCAA provides sample Mathematica solutions, and it is telling that these solutions are clumsy, uninventive and calculator-mimicking, suggesting a limited understanding of Mathematica’s capabilities.

Whatever naivete may exist, I believe it is unlikely to last. Nothing precludes the marketing of Mathematica packages designed specifically for VCE testing and, if Mathematica becomes widely available in VCE, I believe this commercialisation is inevitable. Such a development would turn VCAA’s implementation of Mathematica, which is already very problematic, into an obvious farce. 

Of course the MAV having cut these paragraphs, along with every single reference to the VCAA, doesn’t make their content any less true, any less obvious or any less important.

We intend to write more later in the week.

Guest Post: Mathematica and the Potential Gaming of VCE

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July 16, 2020

2:11 pm

42 Comments on Guest Post: Mathematica and the Potential Gaming of VCE

Uncategorized, VCE

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What follows is the article Mathematica and the Potential Gaming of VCE, by Sai kumar Murali krishnan, which has just appeared in Vinculum and which we have written about here. Sai’s article is reproduced here with Sai’s permission. Sai can be contacted by email here. 

 

INTRODUCTION

Last year I completed VCE, including Mathematical Methods (CBE) and Specialist Mathematics. At my school these subjects employed the computer system Mathematica in place of handheld CAS calculators. The CBE (Computer-Based Examination) version of Methods also entailed the direct submission of SACs and the second (tech-active) exam on the Mathematica platform.1

Mathematica is extraordinarily powerful and, as it happens, I consider myself a decent programmer. During VCE, I entertained myself by creating custom functions to automate tedious computations, which I then shared with my fellow students. We were able to store these functions in a paclet (package), ready for use on the SACs and the exam. While handheld CAS calculators can also store (less complex) custom-made functions, Mathematica’s vast in-built library and ease of use moves it into a different class. Mathematica enables the creation of exam-ready functions to perform any computation a student might require.

I have witnessed, and experienced, many problems with the implementation of Mathematica, but in this article I will focus upon the two most glaring and most important issues. First and foremost, Mathematica is so powerful that it can trivialise the testing of the mathematics for which it is purported to be a tool. It enables any student who can program in Mathematica or, more perversely, who has a friend, teacher or tutor who can program in Mathematica, to perform well in VCE mathematics. Secondly, and as an inevitable consequence of this trivialisation, the current partial implementation of Mathematica could create a grossly unfair competition, an unfairness enhanced in Methods CBE by effectively permitting Mathematica code to be submitted as an answer. The students equipped with handheld CAS calculators are the victims. Armed with toys sporting 70s Nintendo displays, they are being outgunned by students deploying full-screen guided missiles.

In this article I will illustrate how Mathematica can trivialise exam questions in Mathematical Methods. In Part 2, I provide an example of the use of Mathematica’s in-built functions. In Part 3, I consider the application of custom-built functions. In Part 4, I summarise, and I indicate why I believe the problems with the implementation of Mathematica are only likely to worsen.

 

IN-BUILT FUNCTIONS

We begin by looking at Question 5, Section B of 2019 Exam 2, which concerns the cubic \boldsymbol{f(x) = 1 - x^3}.

The question first prompts us to find the tangent at x = a, which we perform in one step with the function TangentLine.2 We then find the intersection points Q and P with two applications of the function Solve. Next, the area of the shaded region as a function of a is found by subtracting the area under the cubic from a triangular area: the former is found using the function Integrate, and the latter is found directly from the coordinates using the functions Polygon and Area. Finally, we are required to find the value of a that minimises the area, which is found in one step with the function ArgMin.

What follows is the complete Mathematica code to answer this five-part question:

This solution requires little mathematical understanding beyond being able to make sense of the questions. In particular, the standard CAS approach of setting up integrals and differentiating is entirely circumvented, as is the transcription. In Methods CBE, the above input and output would be considered sufficient answers.

 

CREATED FUNCTIONS

We’ll now venture into the world of custom Mathematica functions, where programmers can really go to town. We’ll first look at the topic of functions and the features of their graphs. Mathematica does not have a built-in function to give all the desired features, so I created the function DetailPlot. To begin, I use a module to gather data about a function, including endpoints, axial intercepts, stationary points, inflection points and, if required, asymptotes. I then turn the module into an image to place over the graph.

Let’s fire this new weapon at Q2(c), Section B of 2016 Exam 2, which concerns the pictured quartic. We are given the equation of the graph and the point A, and we are told that the tangents at A and D are parallel. We are then required to find the point D and the length of AE.

And, here we are:

With very little input, DetailPlot has provided a rich graph, with every feature one might require within easy reach. The intersection points are ‘callouts’, which means that the points are labelled with their coordinates. In particular the coordinates of D and E have been revealed by DetailPlot, without any explicit calculation. We can then press forward and finish by finding the length of AE, a trivial calculation with the in-built function EuclideanDistance.

In the next example I demonstrate that a multi-stage question can still be trivialised by a single piece of pre-arranged code. In the multiple choice question MCQ10 from 2017 Exam 2, the function \boldsymbol{f(x) = 3\sin \left(2\left[x+\frac{\pi}{4}\right]\right)} undergoes the transformation \boldsymbol{T\left(\Big[\begin{smallmatrix}x \\ y\end{smallmatrix}\Big]\right) = \Big[\begin{smallmatrix}2 & 0 \\ 0&\frac13\end{smallmatrix}\Big]\Big[\begin{smallmatrix}x \\ y\end{smallmatrix}\Big]} and we are required to identify the resulting function. For such questions I created the function Transform, and then the in-built function FullSimplify polishes off the question:

My last example is on functional equations, for which I created two functions, FTest and RFTest. I will illustrate the use of the latter function. For MCQ11 on 2016 Exam 2, the equation f(x) – f(y) = (y – x) f(xy) is given and it is required to determine which of the given functions satisfies the equation. Here is my entire solution:

 

CONCLUSION

It is impossible to have a proper sense of the power of Mathematica unless one is a programmer familiar with the package. This article presents just a few examples from the vast library of functions I created for Mathematical Methods and I found even more so for Specialist Mathematics. My libraries for both subjects barely scratch the surface of what is possible.

Creating such packages requires skill in both programming and mathematics, but the salient point is that any subsequent application of those programs by another student requires no comparable skill. The programs I have written may improve the performance of mathematically weaker students. Conversely, any student without access to such programs or, worse, is required to use handheld CAS instead of Mathematica, will be at a significant disadvantage.

This demonstrates the potential power of Mathematica to change the focus of VCE mathematics and, consequently, to debase its teaching and its assessment. True, the same issues had already arisen with the introduction of handheld CAS; clever teachers and cleverer students have always engaged in creating and sharing push-a-button CAS programs. Mathematica, however, has massively elevated the seriousness of these issues, all the more so since only a fraction of students have access to the platform.3

Technology, including Mathematica, calculators, spreadsheets and the many online programs, have tremendous potential to assist students with learning, understanding and applying mathematics. What is important for educators is to be careful that students are not using this technology to bypass learning and understanding mathematics.

1. All non-CBE students take the same tech-active exams and are considered in the same cohort for ATAR purposes. The Methods (CBE) exam appears to differ in only a superficial manner, and it appears that CBE students have not been considered a separate cohort since 2016.

2. The examination diagrams have been redrawn for greater clarity.

3. Although the Victorian Government offers Mathematica to all schools, to date many schools have not implemented it.

© Sai kumar Murali krishnan 2020

WitCH 38: A Deep Hole

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June 20, 2020

3:06 pm

84 Comments on WitCH 38: A Deep Hole

WitCH

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This one is due to commenter P.N., who raised it on another post, and the glaring issue has been discussed there. Still, for the record it should be WitCHed, and we’ve also decided to expand the WitCHiness slightly (and could have expanded it further).

The following questions appeared on 2019 Specialist Mathematics NHT, Exam 2 (CAS). The questions are followed by sample Mathematica solutions (screenshot corrected, to include final comment) provided by VCAA (presumably in the main for VCE students doing the Mathematica version of Methods). The examination report provides answers, identical to those in the Mathematica solutions, but indicates nothing further.

UPDATE (05/07/20)

The obvious problem here, of course, is that the answer for Part (b), in both the examination report and VCAA’s Mathematica solutions, is flat out wrong: the function fk will also fail to have a stationary point if k = -2 or k = 0. Nearly as bad, and plenty bad, the method in VCAA’s Mathematica solutions to Part (c) is fundamentally incomplete: for a (twice-differentiable) function f to have an inflection point at some a, it is necessary but not sufficient to have f’’(a) = 0.

That’s all pretty awful, but we believe there is worse here. The question is, how did the VCAA get it wrong? Errors can always occur, but why specifically did the error in Part (b) occur, and why, for a year and counting, wasn’t it caught? Why was a half-method suggested for Part (c), and why was this half-method presumably considered reasonable strategy for the exam? Partly, the explanation can go down to this being a question from NHT, about which, as far as we can tell, no one really gives a stuff. This VCAA screw-up, however, points to a deeper, systemic and much more important issue.

The first thing to note is that Mathematica got it wrong: the Solve function did not return the solution to the equation fk‘ = 0. What does that imply for using Mathematica and other CAS software? It implies the user should be aware that the machine is not necessarily doing what the user might reasonably think it is doing. Which is a very, very stupid property of a black box: if Solve doesn’t mean “solve”, then what the hell does it mean? Now, as it happens, Mathematica’s/VCAA’s screw-up could have been avoided by using the function Reduce instead of Solve.* That would have saved VCAA’s solutions from being wrong, but not from being garbage.

Ask yourself, what is missing from VCAA’s solutions? Yes, yes, correct answers, but what else? This is it: there are no functions. There are no equations. There is nothing, nothing at all but an unreliable black box. Here we have a question about the derivatives of a function, but nowhere are those derivatives computed, displayed or contemplated in even the smallest sense.

For the NHT problem above, the massive elephant not in the room is an expression for the derivative function:

    \[\color{red} \boldsymbol{f'_k(x) = -\frac{x^2 + 2(k+1)x +1}{(x^2-1)^2}}\]

What do you see? Yep, if your algebraic sense hasn’t been totally destroyed by CAS, you see immediately that the values k = 0 and k = -2 are special, and that special behaviour is likely to occur. You’re aware of the function, alert to its properties, and you’re led back to the simplification of fk for these special values. Then, either way or both, you are much, much less likely to screw up in the way the VCAA did.

And that always happens. A mathematician always gets a sense of solutions not just from the solution values, but also from the structure of the equations being solved. And all of this is invisible, is impossible, all of it is obliterated by VCAA’s nuclear weapon approach.

And that is insane. To expect, to effectively demand that students “solve” equations without ever seeing those equations, without an iota of concern for what the equations look like, what the equations might tell us, is mathematical and pedagogical insanity.

 

*) Thanks to our ex-student and friend and colleague Sai for explaining some of Mathematica’s subtleties. Readers will be learning more about Sai in the very near future.

VCAA’s SAC of Roaming

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October 20, 2019

5:08 pm

10 Comments on VCAA’s SAC of Roaming

SoS

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One type of educational horror that we haven’t yet written about are SACs, those internal assignmenty-examinationy things that make every second week of Year 12 studies a living hell. It is a tricky topic since SACs are school-based, often teacher-specific, and our primary goal is to attack inept authority. In that regard, schools and beleaguered teachers are in a weird middle ground, part victim and part villain, and they already have plenty of critics. Nonetheless, SACs are the sea in which students and teachers swim (or sink), and mathematics SACs are typically appalling; the overwhelming majority of mathematics SACs that we see are pointless, anti-mathematical, error-strewn blivits. So, something has to be written about such SACs of shit. And, we have a plan.

Our hand has been forced a little, however, by an email we received from a VCE student. The student is taking Mathematical Methods CBE, the trial version of Methods that uses Mathematica instead of CAS, and the student wrote about a recent Mathematica-based SAC at their school. We then asked a teacher at the school about the SAC, and they confirmed the students’ report.

This then is the students’ story, exactly as written to me.

I’m not sure of how many other students you know that are doing CBE methods but my sac today served pretty well to show how awful things can go, so a new perspective is always welcome right?

Starting from the top, we have school-provided laptops with Mathematica preinstalled. So we go in, and we have to utilise this thing called a palette which takes control of Mathematica (I have many complaints against the palette) and downloads the SAC from some remote server. No problems here right? Well, I’d imagine 200 people simultaneously downloading an item from a server would MAYBE just MAYBE cause some congestion in the network. Hell breaks loose here, a class has their file downloaded and enters reading time while the other 4 or so classes are in utter chaos. The downloader is failing over and over while also saying it succeeded. This goes on for a good half an hour before the teachers collectively decided that the sac would be rescheduled to Thursday. The class that began reading? Oh, they just stop. God knows what they could have done, taken photos of the sac with a snipping tool, copied the files over, the possibilities are endless. This whole thing is almost appalling yet terrifying because this is what I’ll have to do at the end of the year. I’ve got a load of other concerns, among the unending variety of methods to do a question with Mathematica and how an assessors report would assign marks, to which our official VCAA quiz provided pissant “solutions” that were often wrong.

Anyway, my slightly irritated take on the abhorrent state of the CBE system, which I thought may be interesting to you.

To that, the teacher at the school added the following:

[The former Head of mathematics at the school] made a deal with the devil and agreed to the school doing Methods CBE. I don’t feel the consultation process valued the feedback from myself and other teachers – it was always going to happen despite the misgivings of other teachers. I can’t help but think that my feelings on the issue is the reason I’m not teaching Maths Methods this year (for the first time in 9 years). There are many problems with this deal – it makes my blood boil. The current head of maths is a very decent guy and has done a fantastic job dealing with the mess he inherited.

I heard that the SAC was a disaster and actually saw events unfolding from afar – like watching a car crash in slow motion. Blind Freddy could have seen what was going to happen. As I left school, I saw the VCE coordinator and the current Head of Maths running around grim faced.

All of the student’s concerns are legitimate. Furthermore, the SAC was meant to run until 4.45 pm, so many students will have made alternative and inconvenient arrangements to accommodate this and now they have to do it all over again. Not to mention what it’s done to the stress levels of many students. Not to mention the time and resources that had to be expended re-writing the SAC. At every stage VCAA have washed their hands of CBE problems and left the school to do its dirty work, using the students as the guinea pigs.

Further,

1. The palette provided by VCAA had a bug.

2. The VCAA server failed. VCAA are trying to blame the school for both errors and no apology has been given. Re: The server fail. VCAA said that the school should have downloaded from the server prior to the SAC starting (which is not practical). VCAA are saying everything worked fine at the other CBE schools (which all have small student cohorts as opposed to our school’s cohort of over 200, which makes a big difference).

That’s it. Our own point of view is that SACs are all but guaranteed to be awful and Mathematica in the classroom is all but guaranteed to be awful. Here, however, those predictable awfulnesses are beside the point. The point here is VCAA’s Trumplike level of incompetence combined with VCAA’s Trumplike unwillingness to accept responsibility.

VCAA Puts the “Con” into Consultation

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April 26, 2019

12:35 am

38 Comments on VCAA Puts the “Con” into Consultation

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As we have written, the Victorian Curriculum and Assessment Authority is “reviewing” Victoria’s senior secondary maths, which amounts to the VCAA attempting to ram through a vague and tendentious computer-based curriculum, presented with no evidence of its benefit apart from change for the sake of change. Readers can and should respond to the VCAA’s manipulative questionnaire before May 10. In this post we shall point out the farcical nature of VCAA’s “consultation”, as evidenced by VCAA’s overview and questionnaire.

The overview begins by framing VCAA’s review with the following question:

What could a senior secondary mathematics curriculum for a liberal democratic society in a developed country for 2020–2030 look like?

This is peculiar framing, since it is difficult to imagine how a society being “liberal” or “democratic” or otherwise has any bearing on the suitability of a mathematics curriculum. Why would a good curriculum for China not also be good for Victoria?

One could easily write off this framing as just jingoistic puffery; neither word reappears in VCAA’s overview. It is, however, more insidious than that. The framing is, except for the odd omission of the word “suitable”, identical to the title of the Wolfram-CBM paper promoting “computer-based mathematics” in general and Wolfram-CBM in particular. This paper is the heavy propaganda gun VCAA has procured in furtherance of its struggle to liberate us all from the horrors of mathematical calculation. Though the Wolfram-CBM paper never states it explicitly, this makes clear the purpose of the framing:

“[L]iberal” and “democratic” and “developed” amounts to “rich enough to assume, demand and forever more have us beholden to the omnipresence of computers”.

The VCAA overview continues by noting the VCAA’s previous review in 2013-2014 and then notes the preliminary work undertaken in 2018 as part of the current review:

… the VCAA convened an expert panel to make recommendations in preparation for broad consultation in 2019.

Really? On whose authority does this anonymous panel consist of experts? Expert in what? How was this “expert panel” chosen, and by whom? Were there any potential or actual conflicts of interest on the “expert panel” that were or should have been disclosed? How or how not was this “expert panel” directed to conduct its review? Were there any dissenters on this “expert panel”?

The only thing clear in all this is the opacity.

The overview provides no evidence that VCAA’s “expert panel” consists of appropriately qualified or sufficiently varied or sufficiently independent persons, nor that these persons were selected in an objective manner, nor that these persons were able to and encouraged to conduct the VCAA review in an objective manner. 

Indeed, any claim to breadth, independence or expertise is undermined by the constrained formulation of the questionnaire, the poverty of and the bias in the proposed curriculum structures and the overt slanting of the overview towards one particular structure. Which brings us to the issue of consultation:

There is no value in “broad consultation” if discussion has already been constrained to the consideration of three extremely poor options.

But, “consult” the VCAA will:

The VCAA will consult with key stakeholders and interested parties to ensure that feedback is gained from organisations, groups and individuals.

Well, great. The writer of this blog is a keenly interested stakeholder, and an individual well known to the VCAA. Should we be waiting by the phone? Probably not, but it hardly matters:

The VCAA has provided no indication that the consultation with “key stakeholders” and “interested parties” will be conducted in a manner to encourage full and proper critique. There is very good reason to doubt that any feedback thus gained will be evaluated in a fair or objective manner.

The overview then outlines three “key background papers” (links here). Then:

… stakeholders are invited to consider and respond to the consultation questionnaire for each structure.

Simply, this is false. Question 1 of VCAA’s questionnaire asks

Which of the proposed structures would you prefer to be implemented for VCE Mathematics?

Questions 2-8 then refer to, and only to, “this structure”. It is only in the final, catch-all Question 9 that a respondent is requested to provide “additional comments or feedback with respect to these structures”. Nowhere is it possible to record in a proper, voting, manner that one wishes to rank the Wolfram-CBM Structure C last, and preferably lower. Nowhere is there a dedicated question to indicate what is bad about a bad structure.

The VCAA questionnaire explicitly funnels respondents away from stating which structures the respondents believe are inferior, and why.

The good news is that the manipulativeness of the questionnaire probably doesn’t matter, since the responses will be presumably just be considered by another VCAA “expert panel”.

The VCAA overview gives no indication how the responses to the questionnaire will be considered and provides no commitment that the responses will be made public.

The VCAA overview goes on to provides outlines of the three structures being considered, which we’ll write upon in future posts. We’ll just comment here that, whereas Structures A and (to a lesser extent) B are laid out in some reasonable detail, Structure C looks to be the work of Chauncey Gardiner:

What is written about Structure C in the VCAA overview could mean anything and thus means nothing. 

True, for a “detailed overview” the reader is directed to the Wolfram-CBM paper. That, however, only makes matters worse:

A 28-page sales pitch that promotes particular software and particular commercial links is much more and much less than a clear, factual and dispassionate curriculum structure, and such a pitch has absolutely no place in what VCAA describes as a “blue-sky” review. By giving prominence to such material, the VCAA fails to treat the three proposed structures in anything close to a comparable or fair manner. 

If there were any doubt, the overview ends with the overt promotion of Structure C:

The distinctive proposal … contain[s] aspects which the Expert Panel found valuable … There was support for these aspects, indeed, many of the invited paper respondents [to the 2018 paper] independently included elements of them in their considerations, within more familiar structures and models.

Nothing like putting your thumb on the scales.

It is entirely inappropriate for a VCAA overview purportedly encouraging consultation to campaign for a particular structure. A respondent having “included elements” of an extreme proposal is a country mile short of supporting that proposal lock, stock and barrel. In any case, the cherry-picked opinions of unknown respondents selected in an unknown manner have zero value. 

Though woefully short of good administrative practice, we still might let some of the above slide if we had trust in the VCAA. But, we do not. Nothing in VCAA’s recent history or current process gives us any reason to do so. We can also see no reason why trust should be required. We can see no reason why the process lacks the fundamental transparency essential for such a radical review.

In summary, the VCAA review is unprofessional and the consultation process a sham. The review should be discarded. Plans can then be made for a new review, to be conducted in the professional and transparent manner that Victoria has every right to expect.

Reviewing the VCAA Review – Open Discussion

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April 17, 2019

8:02 pm

4 Comments on Reviewing the VCAA Review – Open Discussion

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The VCAA is currently conducting a “review” of VCE mathematics. We’ve made our opinion clear, and we plan to post further in some detail. (We’ll update this post with links when and as seems appropriate.) We would also appreciate, however, as much input as possible from readers of (especially critics of) this blog.

This post is to permit and to encourage as much discussion as possible about the various structures the VCAA is considering. People are free to comment generally (but carefully) about the VCAA and the review process, but the intention here is to consider the details of the proposed structures and the arguments for and against them. We’re interested in anything and everything people have to say. Except for specific questions addressed to us, we’ll be pretty much hands-off in the comments section. The relevant links are

Please, go to it.

The Wolfram at the Door

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April 17, 2019

8:01 pm

19 Comments on The Wolfram at the Door

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(Note added 20/4: A VCAA questionnaire open until May 10 is discussed at the end of this post. Anyone is permitted to respond to this questionnaire, and anyone who cares about mathematics education should do so. It would be appreciated if those who have responded to the questionnaire indicate so in the comments below.)

Victoria’s math education is so awful and aimless that it’s easy to imagine it couldn’t get much worse. The VCAA, however, is in the process of proving otherwise. It begins, and it will almost certainly end, with Conrad Wolfram.

We’ve long hoped to write about Wolfram, the slick salesman for Big Brother‘s Church. Conrad Wolfram is the most visible and most powerful proponent of computer-based maths education; his Trumpian sales pitch can be viewed here and here. Wolfram is the kind of ideologue who can talk for an hour about mathematics and the teaching of mathematics without a single use of the word “proof”. And, this ideologue is the current poster boy for the computer zealots at the VCAA.

The VCAA is currently conducting a “review” of VCE mathematics, and is inviting “consultation”. There is an anonymous overview of the “review”, and responses to a questionnaire can be submitted until May 10. (Below, we give some advice on responding to this questionnaire. Update 25/4: Here is a post on the overview and the questionnaire.) There is also a new slanted (and anonymous) background paper, a 2017 slanted (and anonymous) background paper, a 2014 slanted (and anonymous) background paper, and some propaganda by Wolfram-CBM.

In the next few weeks we will try to forego shooting Cambridge fish in the barrel (after a few final shots …), and to give some overview and critique of the VCAA overview and the slanted (and anonymous) background papers. (We hope some readers will assist us in this.) Here, we’ll summarise the VCAA’s proposals.

The VCAA has stated that it is considering three possible structures for a new VCE mathematics study design:

  • Structure A.1 – the same warmed over swill currently offered;
  • Structure A.2 – tweaking the warmed over swill currently offered;
  • Structure B – compactifying the warmed over swill currently offered, making room for “options”;
  • Structure C – A “problem-centred computer-based mathematics incorporating data science”.

What a wealth of choice.

There is way, way too much to write about all this, but here’s the summary:

1. Structure C amounts to an untested and unscripted revolution that would almost certainly be a disaster.

2. The VCAA are Hell-bent on Structure C, and their consultation process is a sham. 

So, what can we all do about it? Pretty much bugger all. The VCAA doesn’t give a stuff what people think, and so it’s up to the mathematical heavy hitters to hit heavily. Perhaps, for example, AMSI will stop whining about unqualified teachers and other second order trivia, and will confront these mathematical and cultural vandals.

But, the one thing we all can do and we all should do is fill in the VCAA’s questionnaire. The questionnaire is calculatedly handcuffing but there are two ways to attempt to circumvent VCAA’s push-polling. One approach is to choose Structure C in Q1 as the “prefer[red]” option, and then to use the subsequent questions to critique Structure C. (Update 25/4: this was obviously a poor strategy, since the VCAA could simply count the response to Q1 as a vote for Structure C.) The second approach is to write pretty much anything until the catch-all Q9, and then go to town. (20/4 addition: It would be appreciated if those who have responded to the questionnaire indicate so below with a comment.)

We shall have much more to write, and hopefully sooner rather than later. As always, readers are free to and encouraged to comment, but see also this post, devoted to general discussion.