Partial Sum Scores as Routing Rules in Survey

1 Initial Problem

It is not possible to create routing rules in survey which behave adaptively according to how a user has answered a set of the previously answered questions.

2 Conceptual Summary

We would like to use (partial) sum scores (see the follwoing article).

When a routing is created, it should be possible to select a subset of questions previous to the current question, which are used to create a "partial" sum score.
This partial sum score should then be used in order to decide where the current user is routed next.

The sum score is simply the sum of all answer scores that a user has given in the selected questions.

In order to achieve this, we suggest adding another step (new "step 1") to the rout rula creation, in which the user selects whether the rule is supposed to be based on the score of a single question or on the sum score of multuple questions.

3 User Interface Modifications

3.1 List of Affected Views

• Routing --> Add Rule

3.2 User Interface Details

{For each of these views please list all user interface elements that should be modified, added or removed. Please provide the textual appearance of the UI elements and their interactive behaviour.}

3.3 New User Interface Concepts

{If the proposal introduces any completely new user interface elements, you might consult UI Kitchen Sink in order to find the necessary information to propose new UI-Concepts. Note that any maintainer might gladly assist you with this.}

4 Technical Information

{The maintainer has to provide necessary technical information, e.g. dependencies on other ILIAS components, necessary modifications in general services/architecture, potential security or performance issues.}

5 Contact

• Author of the Request: Lena Krämer und Glaubitz, Marko [mglaubitz], Universität Freiburg
  
• Maintainer: {Please add your name before applying for an initial workshop or a Jour Fixe meeting.}
• Implementation of the feature is done by: {The maintainer must add the name of the implementing developer.}

6 Funding

If you are interest in funding this feature, please add your name and institution to this list.

• Projekt "kosmic" Universität Freiburg

7 Discussion

2018-04-17: There is no such thing as a "Partial Sum Score". 
Sum Score add together ordered items, and then use these sum-scores for subsequent statistics.  An example are screening instruments for mental disorders. Items are mostly ordered, and a sum-score is used as threshold to determine whether someone has a disease or not.
This means all participants MUST answer all questions or no scum score can be computed. If you use sum scores you need to be sure that when comparing the sums all the individuals responded to the same number of questions/items. 
By definition there can be no partial sum score. 
It does not exist. 
Statisticall the use of averages is advised if the requirements for compputing sum score are not met. But this is still very messy. 

8 Implementation

{The maintainer has to give a description of the final implementation and add screenshots if possible.}

Test Cases

Test cases completed at {date} by {user}

• {Test case number linked to Testrail} : {test case title}

Approval

Approved at {date} by {user}.