Dear Suzanne Jensen
I wrote a long reply to this forum and then pressed the "site popups allowed" button in my Google bar and all was lost! Poignant.
I am sorry to say that I do not think I will have the time to write my post all again. In brief then....
There is no way of preventing viewers seeing the source code (assuming they can use a standard browser) if they try hard.
You can do one of two things, or both....
1) Disable their browser so that it is difficult to select "display source". There is code on these forums for doing this.
2) Encode the source code. There is code for encoding the source code in these forums but it would be difficult to have your whole HP page encoded without considerable hacking - by adding some sort of filter such as is used to encode email addresses.
1) If you disable their browser using a popup window, and right click prevention, then the source remains in the cache of the browser.
Additionally you will create problems for students that have popup blockers (as I do!). Please see
2) If you encode the source then (assuming you are letting users use a standard browser) you will have to include the decoding mechanism for the browser to be able to read the source. A computer savvy student will see what is going on.
E.g. one way of encoding the source is to use the sort of technique used by the attached file. (Search for "Rob Butner" on these forums for an example) But your students will be able to find the decoder at this page, among others.
All the same, using a new popup page and encoding would make it difficult to view the source, perhaps more difficult than doing the test, so my vote is to include these measures. If we had a budget then we would be able to pay for these measures to be included in future editions of moodle.