STACK demo course updated.

STACK demo course updated.

by Christopher Sangwin -
Number of replies: 3
Picture of Particularly helpful Moodlers Picture of Plugin developers

Dear all,

We've been using STACK 3 since September here in Birmingham, and I'm very pleased to report how successful this has been. The period has seen us fix a number of minor bugs, consolidate the design in some areas and generally make substantial improvements.

It gives me great pleasure to announce the release of a significantly update "Demonstration course" for STACK 3.0. This contains about 450 STACK questions licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

This is distributed with the latest qtype_stack code, in the directory "samplequestions". Anyone running STACK already will need to update their code to the latest version in order to run all the questions in this course successfully.

There are comprehensive question sets in algebraic manipulation, and in procedural practice of calculus. There are also a number of other demonstration questions, arranged into quizzes.

These should act as a useful starting point for question authors.

The majority of questions have

  • random versions (where appropriate)
  • general feedback, i.e. a worked solution
  • specific feedback to common incorrect answers
  • question tests,

A number of random versions have been deployed, and the questions arranged into quizzes of reasonable lengths.

The primary aim of this course is a demonstration, hence without a specific group of students in mind some of the worked solutions and feedback inevitably looks inconsistent. This is compounded by the compilation of questions from a number of authors. If you make use of these materials in any ways I'd very much appreciate a short update on your experiences.

I would be delighted to included quizzes in other areas of mathematics as demonstrations. Please send me your materials!

Chris Sangwin

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In reply to Christopher Sangwin

Re: STACK demo course updated.

by Andreas Schneider -

Dear Chris,

Thank you very much for this interesting demo.

My job is to evaluate if, and how, STACK could be used at a vocational school in Switzerland. (As every student has its own laptop at school, we try to do the exams with Moodle). I think I got the idea of what STACK is capable to do and I believe it is a great tool. I managed to author a few questions with the provided instructions. My problem is: I don't understand STACK enough (yet) to work professional with it. For example: the result of a simplification is: (2t+5s)/(st). Stack accepts figures like (10t+25s)/(5st) as correct, even with the LowestTerms function or lowesttermsp. I tried almost everything, but I don't get it right. My question is therefore: Is it possible to see what was typed in Moodle to create the demo questions? Or is there a place where I can ask questions on how to author a specific question? (I'm happy to give something back if I can). Or could you show me what exactly I have to type in Moodle, to solve the lowest terms problem mentioned above?

I would very much appreciate an answer, and thank you in advance,

Andreas Schneider

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In reply to Andreas Schneider

Re: STACK demo course updated.

by Christopher Sangwin -
Picture of Particularly helpful Moodlers Picture of Plugin developers

Andreas,

Thanks for contacting me.

Yes, STACK is designed exactly to assess this kind of question. Have you tried to use the "Maxima sandbox"? This enables you to test maxima using the code loaded by STACK.

http://stack.bham.ac.uk/moodle/question/type/stack/doc/doc.php/CAS/STACK-Maxima_sandbox.md

Using the sandbox, we get the following results:

lowesttermsp((10*t+25*s)/(5*s*t));
false

lowesttermsp((2*t+5*s)/(s*t));
true

The LowestTerms answer test checks that all *numbers* written in the first expression are in lowest terms. If you want to check whether a rational polynomial is written in lowest terms, this is not the test to use. Instead, apply the predicate functions lowesttermsp to the expression.

Is there a particular question in the demo course which isn't working correctly?

I've attached a STACK question which tests this.

I hope this helps,

Chris

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In reply to Christopher Sangwin

Re: STACK demo course updated.

by Andreas Schneider -

Dear Chris,

Thank you very much for your answer. It helped me to solve my problem I had with “lowestterms”. I have now a way of asking questions electronically which works completely well. For example: simplify: r/s + 4/t – (2r-10)/(2s). The students get marks  when they get a single fraction, (with singlefrac), and they get further marks in the second knot if the fraction is in lowest terms. I consider partial points as an important feature.

My problem was, that I haven’t assigned any variables, I only used "ans1" and I tried singleFrac from “answer test” instead of AlgEquiv, Sans SingleFrac(ans1)

My next step will be to create more questions and I’m going to do a test run with students, as well as teachers, to find hidden mistakes.

“Is there a particular question in the demo course which isn't working correctly?”

I haven’t found one so far.

Andreas

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