|
From: SourceForge.net <no...@so...> - 2003-09-03 07:01:33
|
Bugs item #798640, was opened at 2003-09-02 00:14 Message generated for change (Comment added) made by gregg0 You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=439479&aid=798640&group_id=44411 Category: Marking Group: None Status: Open Resolution: None Priority: 8 Submitted By: Ken Monks (monks) Assigned to: Nobody/Anonymous (nobody) Summary: Sporadic Validation error: bad name x Initial Comment: When Trying certain questions or quizzes, AiM reports "Validation error: bad name x." where x can be any single letter variable name that occurs in the answer that is provided by AiM (which is the correct answer). The error is not repeatable. When a question in a Tried quiz produces the error, Trying that same question separately with the same answer will not reproduce the error. I have only noticed this with AiM supplied answers when Trying a quiz or question, not when entering answers by hand as a registered student (but I haven't tested that as frequently, so it is possible it happens there also). ---------------------------------------------------------------------- >Comment By: Greg Gamble (gregg0) Date: 2003-09-03 15:01 Message: Logged In: YES user_id=766524 I can confirm the problem does occur with Maple 8 and the latest development version of AiM. Regards, Greg ---------------------------------------------------------------------- Comment By: Ken Monks (monks) Date: 2003-09-03 10:49 Message: Logged In: YES user_id=766386 After much trial and error I narrowed the problem down to the following reproducible error. If you make a quiz that contains the following two questions in the order given: nm> Question1 l> x h> x:=1; t> x is defined here! a> 1 end> nm> Question2 l> x t> But we still have x=1 here, even though x prints as @x@! a> x end> When you Try this quiz as an administrator, the value of x from the first question is reported by the second question in the validation error (using Neil's suggested modification in this thread to view its value) even though the teacher's answer and the @x@ both report their values correctly as x. Note that this error doesn't occur if you attempt the same quiz as a student and enter the same answers that are provided in the Try quiz page, nor does it occur if you try the second question separately. Also this error occurs on my system using Maple 9 and the latest development version of AIM, but it doesn't occur on my Maple 8 system using version 2 of AIM. So either it is something new with Maple 9, or something we introduced into the current development version. Can someone with Maple 8 installed see if the error occurs with Maple 8 and our development version of AIM? That would at least narrow the problem down somewhat. Suggestions? ---------------------------------------------------------------------- Comment By: Neil Strickland (npstrick) Date: 2003-09-02 05:56 Message: Logged In: YES user_id=430681 This error means that when `aim/SafeParse` is called to parse the student's answer, the global variable x has somehow acquired a value. This is not supposed to happen, even if the relevant question file assigns a value to x, because of the way that the functions `Local/Save` and `Local/Restore` are used. However, it is possible that this mechanism is faulty. If you are seeing this error, please let me know whether the relevant variable occurs in the local variable list for your question, and whether it gets assigned a value. Please also replace the line report['BadName'] := nam; in SafeParse.mpl by the line report['BadName'] := sprintf("%s has value %A",nam,eval (convert(nam,name))); This modification is not safe against hacking, so it should only be inserted temporarily. However, it will at least report what value has been assigned to the bad name, which should help to pinpoint where the assignment occurred. ---------------------------------------------------------------------- Comment By: Gustav W Delius (gustav_delius) Date: 2003-09-02 03:56 Message: Logged In: YES user_id=737246 This bug is hitting me too. The problem is reproducible as long as the quiz is not changed. However deleting other unrelated questions of the same quiz can make the problem go away. The bug shows up when trying a whole quiz as administrator. For me it is still there if I click on "Try separately". However if I then press "New Version" or "Mark" on the single-question page the error goes away. Pressing "Mark" or "New Version" on the page with the whole quiz does not make the error go away. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=439479&aid=798640&group_id=44411 |
