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This document contains current plans and ideas for the Quadbase site.
License Options
Currently, Quadbase has a Licenses table and associates each question with an
entry in that table. CC-BY 3.0 is the first license we'll be using, but there
has been at least initial consideration for allowing the user to choose from
a set of allowed open licenses. This seems like a reasonable idea, but it does
raise a number of issues that will need to be dealt with before a multi-license
system can be implemented:
* Of course, just as with our current setup with CC-BY 3.0, each license would
need its own agreement view partial.
* Different license place different restrictions on whether or not the license
can be changed in derived questions or in new versions of questions. This
might be achievable with simple "can_change_on_new_version" or "can_change_
on_derivation" boolean flags on each license record. However, depending on
the ins and outs of various licenses, we might need something more complex
like a matrix of sorts that keeps track of which licenses can be changed to
which other licenses for versions and derivations.
* Things get more complicated if, as might be necessary, we need to look back
through the version/deriviation history to make sure a license change is
allowed (e.g. maybe license A can be changed to license B, and license B
can be changed to C, but A can't be changed to C). This sounds hard.
* With multiple licenses in a history of derivations and versions, it may be
difficult to make sure we get attribution statements correct.
For the time being, the system will be restricted to have only one license. We
will leave the Licenses table as it is, and will continue to link questions to
licenses. We may end up modifying the views (and some initialization) routines
so that folks don't even really see that there is a 1-choice-only option for
which license to choose (which may be confusing).
-- Possible idea for simplifying multiple licenses --
If we do end up pursuing a multi-license strategy for Quadbase, one nice
simplification might be to allow the author of a brand new question to
choose whichever license they want, but to disallow folks who make new
derivations/versions from changing from that initial license. This is not
to say that all licenses require this "never change me" behavior, but just
that Quadbase would say that. In this approach, Quadbase isn't limiting
folks' ability to change licenses as allowed by whatever license they're
dealing with; Quadbase is just saying that possibility is not allowed on
the Quadbase site.
Question Dependencies vs Supports
Sometimes an author will write a multi-part question where there answer
from one part is required to answer a following part, e.g.:
Intro: x(t) = t^2
Q1: Calculate y(t) = \int x(t).
Q2: What is y(t) at t = 0?
We call Q1 a prerequisite question for Q2. Q2 can never be shown without
showing Q1 first. Q2 is dependent on Q1.
There are also times when the answer to one question might help a student
answer another question (though that helping question doesn't have to be
seen first).e.g:
Intro: A 1 kg sphere falls from a height of 1 km in a uniform atmosphere
with constant pressure of 1 atmosphere.
Q1: what is the balls terminal velocity?
Q2: when will the ball hit the ground?
A student could be asked Q2 independently. The answer to Q1 helps solve
Q2, so if it is marked as a supporting question for Q2, the student could
be asked Q1 if he/she misses Q2. That is, it can be used as a scaffold
through which the student can work to answer the final question Q2.
Eventually, these supporting questions could be rated by how much they
support another question ("gives it away", "only helps a little bit", etc)
and these levels of support could be used in deciding how much to help
the student.
These two types of data essentially just need to be recorded as pairs of
question IDs in a table. Since they are logically different and the
support associations might eventually have grades or levels of support
attached to them, we will create two separate tables and models for these
These other questions can often be used as a fallback scaffold
if the student misses
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