Forum OpenACS Development: error raised when activity appears in several role-parts

18: error raised when activity appears in several role-parts (response to 1)

Posted by Michael Totschnig on 03/21/06 09:36 AM

I am testing the imsld package with some of the learning designs found on http://moodle.learningnetworks.org/ in the "Runnable LD Example Units of Learning" node. When I tried http://hdl.handle.net/1820/316, I realized following problem:

When an activity is referenced in several role-parts, following error is raised, upon access to a resource.

Database operation "0or1row" failed (exception NSINT, "Query returned more than one row.")

SQL:
select item_id as rp_item_id, role_part_id
from imsld_role_partsi
where activity_structure_id = '3854'

The solution probably consists in passing also the act where the activity appears to the get_role_part_from_activity function. Unless, you return all role_parts where the activity is referenced, and mark them finished. But this would mean that the activity gets marked as finished for all plays where it appears.

This raises a more general question I wanted to ask you: In the design of the imsld package, I could not find the concept of a "run" that instantiates a learning design, and that would make it possible to restart the delivery from scratch with a new run if desired. Is this something you plan to add?

19: Re: Res: error raised when activity appears in several role-parts (response to 18)

Posted by Jose Pablo Escobedo Del Cid on 03/21/06 11:55 AM

Michael, thanks a lot for the feedback. Your are helping us a lot.

We were dealing with that bug now. We think its' better to mark the activity finished in all the role parts that references it. What do you think?

About the other question, we haven't plan about multiple runs of the same UoL, but that could be possible, as you say. All we need (the info in the db) is there, so it would be just to add the API to do it. We will take it into account for our future developments/goals.

Regards

20: Re: Re: Res: error raised when activity appears in several role-parts (response to 19)

Posted by Michael Totschnig on 03/21/06 01:22 PM

I am wondering if you do not need the concept of a "run" if you deal with multi-user learning_designs where you "enroll" users to a unit of learning, assign them to roles, before you start delivering it, and have to keep track of them as the community of users participating in the same "run", as suggested in the "Implementation guide" of the specification.

Regards,

21: Re: Re: Res: error raised when activity appears in several role-parts (response to 19)

Posted by Michael Totschnig on 03/22/06 10:34 AM

Sorry, I forgot to react to the first point. I am not sure if marking the activity finished for all role parts where it is referenced, is what is intended by the specification.
If you think of a learning design with two plays, which both reference the same activity, but in two different contexts. If a user first executes play 1, and passes the activity, and later he executes play 2. When it comes to the activity he already has passed in play 1, it could possibly make a different sense in the new context, and if it had been already marked as finished, the flow of play 2 could become disturbed, or in the first case no longer make sense.
Does this make sense?

22: Re: Re: Re: Res: error raised when activity appears in several role-parts (response to 21)

Posted by Luis de la Fuente on 03/22/06 12:08 PM

Sure, we have also thougth about this fact. The problem appears when the same activity is referenced from two different places, no matter if we are talking about role-part, environmente or plays, the fact is that you have to do the activity twice.

On one hand, the activity has different meaning into different contexts. Another point of view is that the activity is the same, and you can do again this activity, no matter if it have been finished or not. That means: if you have already done an activity and it's time to do it again from another place (role-part, play, etc.) the activity is shown and you can do it again.

Copper-Core behave like .LRN IMS-LD in this sense.

23: Re: Re: Re: Res: error raised when activity appears in several role-parts (response to 20)

Posted by Luis de la Fuente on 03/22/06 01:14 PM

Currently, we are working on the support of roles into the application. When finishing this task, the information about completed resources will be: user_id, role_id, role_instance_id, resource_id.
With this, before delivering a unit of learning, you must assing roles. Moreover, to reply an IMS-LD you will only have to re-instance a role, and the resources will appear as not-completed, and the imsld will be replied.

All this features are on development. We can call for test before commiting on CVS.

24: Re: Re: Re: Res: error raised when activity appears in several role-parts (response to 20)

Posted by Jose Pablo Escobedo Del Cid on 03/31/06 05:11 PM

Michael,

We are right now working on supporting multiple runs for the same UoL. So the first thing the professor will have to do after uploading an UoL is to assign users to the run. Then the roles instances, properties instances, etc. will refer to the run (instance of the UoL).

More specifically, I was thinking about adding a "imsld_runs" table, which will map the run with the ims_ld_id. Then the instance of the roles will be made with the users which are assigned to the run, and the "status" table will also store the run_id. Also, the properties instances will refer This way there may be multiple runs for the same UoL.

Do you have any comments?

25: Re: Re: Re: Re: Res: error raised when activity appears in several role-parts (response to 24)

Posted by Michael Totschnig on 04/06/06 05:24 PM

Jose,

sorry for the late reply. What you describe seems reasonable to me. If you already have something up ready for testing, I would be glad to try it and give you detailed feedback.