1 Continuing with our Domain Model

First, a quick recap:

1.1 Problem Statement

ODU offers a number of courses via the internet. A common requirement among these courses is for a system of online assessment. An assessment is any form of graded question-and-answer activity. Examples include exams, quizzes, exercises, and self-assessments. In preparation for automating such a system, our group has undertaken a study of assessment techniques in traditional classrooms.

An assessment can contain a number of questions. Questions come in many forms, including true/false, single-choice from among multiple alternatives, multiple choices, fill-in-the-blank, and essay. There may be other forms as well.

Students take assessments that are administered by instructors. The students’ responses to each question are collected by the instructor, who grades them by comparison to a rubric for each question. The instructor may also elect to provide feedback (written comments), particularly about incorrect responses.

A total score for the assessment is computed by the instructor. If this is a self-assessment, the score is for informational purposes only. For other kinds of assessments, the instructor records the score in his/her grade book.

Information is returned to the student about their performance. At a minimum, the student would learn of their score and any instructor-provided feedback. Depending upon the instructor, students may also receive the questions, a copy of their own responses, and the instructor’s correct answer.

1.2 Where We Ended Up

So far, we have diagrammed a number of classes, adding attributes and operations to a number of them:

We also had a handful of classes that we set aside in our first pass as variants of a more general case that we were looking at in detail:

2 What Isn’t Captured in Our Class Descriptions?

Let’s look for things that we learned but that the CRC cards don’t really capture.

2.1 Different Kinds of Assessment

ODU offers a number of courses via the internet. A common requirement among these courses is for a system of online assessment. An assessment is any form of graded question-and-answer activity. Examples include exams, quizzes, exercises, and self-assessments. In preparation for automating such a system, our group has undertaken a study of assessment techniques in traditional classrooms.

• Read the diamond-shaped arrow (aggregation) as “is part of”.
• Read the open triangular arrow (generalization) as “is a specialized kind of” (or sometimes just “is a” for short.)

2.2 Different Kinds of Question

An assessment can contain a number of questions. Questions come in many forms, including true/false, single-choice from among multiple alternatives, multiple choices, fill-in-the-blank, and essay. There may be other forms as well.

Suggests another generalization relationship.

2.3 Documents Involved in Grading

Looking at this paragraph overall, there is a more subtle set of relationships not captured in our class descriptions.

Students take assessments that are administered by instructors. The students’ responses to each question are collected by the instructor, who grades them by comparison to a rubric for each question. The instructor may also elect to provide feedback (written comments), particularly about incorrect responses.