Open Source e-Learning
  • Login


Icoon Wiki

Feature Wiki

Information about planned and released features


STACK Question Plugin

This is the central page for the development of the STACK Question plugin. If you want to contribute ideas for future developments of the STACK Plugin, please create a new feature wiki page and link it in the list below.

The SIG Mathe Digital has to discuss a feature first (!) before the implementation can be started.

The procedure for new features of the STACK plugin is...
  • create a feature request page for your proposition
  • schedule a meeting / VC with the SIG Mathe Digital by contacting Stefan Koospal or Wigand Rathmann
  • discuss your feature request with the SIG Mathe Digital
  • you should get an answer in at least 14 days or the request get the status accepted
  • The maintainers of the plugin decide on the implementation of the feature based on the discussion results of the SIG
  • if funding is provided (e.g. by you) the implementation can start...

1 Status

  • Implementation as plugin
  • Funding for initial implementation collected through fundraising, see Crowdfunding data collection
  • Development: Implementation of the feature is done by Jesús Copado, Uni Erlangen
  • Status: 
    • Version 1 for ILIAS 4.4 (only import) is published in August 2014. 
    • Version 2 for ILIAS 5 (with authoring interface) is published in February 2015 (Git branch 'master')
    • Version 2.4 for ILIAS 5.2 is published in May 2017 (Git branch 'master-ilias52')
    • Version 2.5 for ILIAS 5.2 and ILIAS 5.3 with STACK core 3.3 is plublished in December 2017 (Git branch 'master-ilias52')
    • Version 3.0 for ILIAS 5.2 and ILIAS 5.3 with STACK core 4 is plublished in March 2017 (Git branch 'master-ilias53')
  • Publication:

2 Additional Information

Old Version of this Page
Testing in Mathematics and other nature sciences requires test question types that support calculation, formulas and equations. Neither simple multiple choice questions nor formula questions can fulfill this requirement because these question types only check the given answer against a predefined set of numbers and characters. They are not calculating the result and accepting different submissions with the same value, e.g. 2 and 4/2.
Possible Solution
A question type that checks the given answer by using a Computer Algebra System (CAS) would solve this problem and allow to offer valuble and helpful test&assessments to students.
A well matured and proven use case for a CAS connection is STACK which offers a connection to the popular MAXIMA CAS. A STACK plugin is already available for Moodle and often used. It would be a reasonable approach to adopt the Moodle plugin for STACK and port it to ILIAS. But this requires to get off all Moodle specific code out of the plugin and to transform it to a ILIAS compatible plugin.
For the implementation we need to distinguish between the learner view and the author's side of the question editor. While the presentation of a CAS question only needs to deliver a connection to the CAS which is hosted somewhere, the authoring side of creating a CAS question is different and much more challeging.
Learner View
The learner's view needs only to support the CAS connection and deliver the input given by the learner to the CAS. The result processed by the CAS is send back to ILIAS and determines the result of the answer. According to the result points are given to the user for this answer.
Workaround for a first implementation
Facing the situation that a full funding of the CAS question type cannot be offered immediately, a two-step solution seems to be a reasonable strategy to implement the feature as soon as possible:
In a first step only the learner's view of this question type is implemented while the editing of the question still takes place in a STACK plugin embedded in Moodle. STACK questions created by Moodle are exported and transformed to ILIAS compatible question types that can easily be imported. Such CAS questions can become part of a test question pool in ILIAS.
The following sub tasks are needed to develop an ILIAS plugin for the Learner View of STACK questions:
  1. Technical conception of the plugin and coordination with the developers of the original STACK question type (to ensure that platform specific and independent parts can be separately developed in the future)
  2. Development of the plugins basic architecture and the data structures to save the definition of stack question
  3. Development of the technical interface to the platform independent part of STACK (if needed, with wrappers for current moodle specific classes and function calls)
  4. Development of a conversion for exported questions from STACK in moddle to STACK in ILIAS (single question and question pools)
  5. Conception of the user interface for the Learner View: preview, execution, result ans print view of STACK questions result and print view
  6. Implementation of the user interface for the Learner View
Authoring Environment
In a second step the authoring environment of such a CAS question type has to be implemented as a plugin for the question type plugin slot. Such an authoring interface needs to offer all options for defining a CAS question.
Matthias Kunkel, 20 Mar 2014: A first prototype of the learner interface will be presented end of March on the team meeting of optes project in Detmold. An additional presentation is planned for the DevConf at March 27 in Münster. The development of the authoring interface starts end of April and is currently scheduled until July/August.
Matthias Kunkel, August 08, 2014: A first stable version of the question plugin has already been published, see It allows to import STACK questions developed in Moodle and to run them in ILIAS tests.
Fred Neumann, February 06, 2015: version 2 (beta) with an authoring interface is now available, see

3 Feature Requests

4 Implemented with STACK Plugin Version 3.0

Laatste wijziging: 17. Dec 2019, 10:28, Koospal, Stefan [koospal]

Zoeken (Blok)

Wiki Functies (Blok)


Recente wijzigingen