1. | quiz | Quizzes. Each quiz has a unique key (qkey); each row represents a single quiz. |

2. | quizanswers | Each problem may have multiple "rows" of answers, e.g. a three-choice multiple-choice problem has 3 rows which define the possible answers. |

3. | quizmap | Maps sets of problems to a quiz. This tells us which quizzes "own" or "contain" which problems. Each row relates (connects) one problem to one quiz. |

4. | quizproblems | Each problem has a unique key (pkey); each row represents a single problem. |

5. | quizscore | Records Takers' scores on problems. One row per Taker/problem/quiz/session combination. (Allows for a single problem to be shared across multiple quizzes, and also for taking a quiz more than once.) . |