The fact that your items are simple, doesn't yet guarantee that they are easy to remember. One of the powerful obstacles in creating easy knowledge systems is the problem of interference, or confusion, coming from the fact that two different items might have similar questions or similar answers. For example, imagine that you want to learn something about SuperMemo, and you create a special knowledge systems devoted to that purpose. Consider the two following items of your knowledge system concerning SuperMemo:
A: ambiguous items
A: equivocal items
A: a. ambiguous items OR
b. equivocal items
the student might memorize the universal list of 10 pictures corresponding to 10 digits e.g.:
1 - harpoon (because 1 looks like a harpoon),
2 - coin (because a coin has two sides),
3 - tripod (because a tripod has three legs),
4 - dog (because a dog has four legs), etc.
and formulate the mnemonic item in the following way:
A: What is the value of the constant p?
Q: 3.14 because: p rhymes with fry and ... on a small tripod a big balloon is being fried (balloon represents the decimal point), suddenly somebody pierces the balloon with a harpoon, and from inside the bursting sphere a big dog jumps on the student.
Although construction of the pictured scene may seem awkward and time consuming, it ultimately yields items that in most cases are much easier to remember than those composed of dry numbers. The net result is saved time.