Plugins are nice, but we need to ensure that question types work after an update. Our professors would not use it, if they need to be afraid that it does not work after an update.

JF 28 Jun 2010: In the case of question plugins for the test and assessment component we let the maintainer (Helmut Schottmüller) decide which question type should become a core feature and which not, since he knows how many times a question type has been requested by users.

Shortly after the JF above we talked to Helmu Schottmüller about that feature. He told us that he had passed all his projects to databay. The reson why he hadn't put formula questions to core was that the units are not binded to the questions and can be changed from every "question editor" for the whole ILIAS installation.
 
So we contact databay to develope a soloution for that together. Result is a new Pluginversion published here. Now question editors need to copy units from pool categorys to thier questions or enter new ones, bevore they can use them. Pool categorys are only changeable by administrators.
 
Additional we added a feature where you can chose the result type: each, decimal, fraction coprime fraction.
 
We think formular questions are now ready to become a core feature. Please discuss again.

JF 19 Dec 2011: We ask Jan Posselt, the current T&A maintainer to participate in one of the next Jour Fixes and make a presentation. We then will decide on its integration into the core.

2012-04-03 J. Erkens FH Aachen: No decision yet?

JF 2 May 2012: Björn Heyser is the new maintainer of the T&A component. Up to now he was not able to make a presentation of this plugin at the JF.

2012-12-06 J.Erkens FH Aachen: What's up with Björn Heysers or Jan Posselts Presentation? We are highly interested in funding core integration.

JF 10 Dec 2012: There was no presentation yet but we still appreciate to have this question type in the core. Please get in contact with Björn Heyser bheyser (at) databay.de to trigger some progress. We schedule a presentation of this feature and possible migration into the core for the next Jour Fixe (January 2013).

2013-01-25: Presentation will take place on JF 5 Feb 2013.

JF 5 Feb 2013: We appreciate the feature and support the move to the trunk with 4.4. The interface should be streamlined and structured (e.g. subheading should be used in forms) and import/export should work. Jochen Erkens will put some screenshots of the editing screens into this page. We will continue to discuss the interface.

BH, 27. Feb:
 
The further discussions should not only involve the user interface, but also the technical/conceptional issues mentioned by the HS Karslruhe. Not all of them are quit fixable I think.

JE, 27.2.2013:
Discussion issue by issue in mantis? "Not all of them..." is a little bit general.

JE, 27.2.2013:
Added our current version of formula plugin manual for version 4.2.

JE, 22.3.2013:
A first interface suggestion for question editor:

Alex Killing, 22 Mar 2013: @JE This is a big improvement, I like it.

Mikko Vasko, 28 Mar 2013: Here are a couple of ideas/requests our professors would like to see in the Formula Question Type:

• Possibility to exclude certain numbers when defining variables, for example "$v1= -5...5, exclude 0" or "$v2=2...10, exclude 3,5,7,9"
• Add following functions: factorial (n!), exponential function exp(), error function erf()
• Possibility to combine multiple choice questions and formula questions (similar to cloze/Lückentext-question)
• Exponent should accept rational numbers (currently only integers are accepted).