Activity aim: Students should learn to strip sentences down to basic components necessary to determine the elements of ERD. They will learn to spot nouns and verbs in each sentence, and translate them into Entities and Relationships elements accordingly. Subsequently they will learn to extract necessary information from the sentence to determine cardinality and optionality of a relationship, and display them on the diagram. Students will learn to spot a category of an entity.
Materials: Printed worksheets
Time estimated: 20 minutes
Prep for teacher: Set up worksheets. Break up students into about 6 groups of 6-7.
Note: This is designed for a class of >40 students.
Description:
Prior to the class, the instructor will prepare enough copies of the worksheet described below so that each group has one.
At the start of the activity instructor displays on the projector screen the worksheet with the first sample sentence that needs to be converted into graphic components of an ERD diagram.
These are examples of the sentences. They cover one-to-one, one-to-many, many-to-many, optional and mandatory, and category concepts.
1. Each student can be enrolled in only one college.
2. A college has many departments.
3. Each department has many instructors. Each instructor belongs to exactly 1 department
4. Each student takes up to 5 classes (a semester). Each class contains no more than 50 students.
5. Each instructor teaches up to 4 classes (a semester). A class can have up to 2 instructors.
6. Each student must declare an academic plan by sophomore year. Academic plans are majors and minors. Each student can have 2 majors and 3 minors.
Students will be broken into groups, with people next to them and behind them, so the 3 rows of pairs are formed, and each group will be assigned a sentence to consider, and given time to sketch the elements on their own. (5 minutes.)
Next, students will be asked to discuss their solution with the partners. This discussion will last another 5 minutes. The group sketch should be developed at this stage.
After the discussion, instructor asks each group sketch their solution on the white board. The instructor asks the group why they used these elements and cardinality. Then the instructor asks the next group to comment, and agree/disagree/provide explanation and so on. Eventually all sketches are displayed. This discussion lasts 10-15 minutes.
In the next stage the instructor connects the individual diagrams into a complete Entity Relational Diagram for the whole assignment.
This activity was developed by Paulina Vizgan as part of the Baruch College Center for Teaching and Learning Summer Seminar on Active Learning.