Glenys,
I understand what you want to do, but I would like you to understand the consequences of allowing guests in.
Some teachers want the HotPot module to stop students "cheating". They expect that a student should only allowed to be able to do one attempt at a time. If students could do two attempts simultaneously, they could open two separate browser windows, start two separate attempts, and use one to discover the correct answers, and the other to input the right answers. They could thus achieve a perfect score without the effort and knowledge that the teacher was trying to elicit.
For this reason, the HotPot module does not allow simultaneous attempts. When a user starts a new attempt at a HotPot activity, all the previous "in progress" attempts at that activity by that user are set to "abandoned", and the new attempt is set to "in progress". If the HotPot module receives results for an attempt that is "abandoned", it will refuse to store the results and will instead display a message saying something like "That attempt is not in progress".
There is another possible complication of allowing guest users in, if you also allow your site to be open to Google and other search engines. If the search engines are allowed in to Moodle, they will be logged in as the guest user. If they are looking at the course page or resources or assignment explanation pages there is no problem, because the content on those pages doesn't change. However, if we give the search engine access to a HotPot page there is a good chance that the content is different every time, so the search engine will think that the page has been updated and will come back again and again to get the "latest" version of the page. Search engines are relentless and will keep coming back. Your server will be have to work to serve up the pages to the search engines, and depending on how many HotPots you have and how powerful your server is, your server may get overwhelmed.
This problem can be compounded if you let the guest user be a teacher in a HotPot/QuizPort activity, in order to give them access to the "Preview" button. Now the search engine has access to the report pages, which change each time a student attempts a quiz. Remember that if you have allowed the search engine to attempt the HotPot quiz as a guest user, then those attempts will appear on the report page. The search engine will be endlessly trying to access the HotPot quizzes and report pages, and your server will be frantically trying to keep up. I have seen this perfect storm in action, and it took the server down within hours.
The problem then is that the HotPot module and QuizPort module are designed and built assuming no guest access. This allows them to ignore simultaneous attempts and rules out the possiblity of search engines making uncescessary and excessive access to quiz and report pages.
We could argue that for small sites or sites wishing to showcase online materials that don't cause a search engine feeding frenzy the above objections to guest access do not matter. However, if we make any changes to allow "easy" guest access, we must realize that this could affect the very core method of how these modules work, and could lead to confusion among many teachers as to "why has my site gone down, when all I did was enable guest access to HotPots".
From my point of view, I think the most complete answer to this issue is to change the login scripts in Moodle core to allow dynamically-assigned multiple and separate guest access. In such a system, when a user requests guest access, the system will check to see if any already created guest account is currently logged out. If such a guest account exists, the user will be logged in using that guest account. If no guest account is available, a new one is created. If the user was given a previously existing account then all previous Quiz and HotPot (and QuizPort) attempts are removed, so that the user starts their Moodle access with a clean slate.
You can see such a system in action at the following site. You will notice that when you log in, you are given a user name such as "FNE Guest (3)", when the number in brackets indicates which guest user you are logged in as. Here is the URL:
In the interests of openness, I should say that the above site is run myself and a buddy. It is free to use. I am offering it here simply as an example ofmultiple separate guests on Moodle. You should be aware that the programming required for that feature required several months work (in 2009), and is not a task I would suggest you undertake without a lot of understanding of what is involved.
regards
Gordon