Presentation on theme: "Modelling with databases. Database management systems (DBMS) Modelling with databases Coaching modelling with databases Advantages and limitations of."— Presentation transcript:
Database management systems (DBMS) Modelling with databases Coaching modelling with databases Advantages and limitations of modelling with databases
Database management systems (1) Database management systems (DBMSs) are computerized record-keeping systems. They are originally designed to replace paper-based information retrieval systems. A DBMS is in effect an electronic filing cabinet that allows users to store information and later retrieve information. The advantage of computerized information storage includes : compactness speed of entering information, fast and easier access to information and easing updating of information.
Database management systems (2) DBMS: Components and tools A DBMS consists of several components: The database A database consists of one or more files, each of which contains information in the form of collections of records that are related to a specific content domain. Each record consists of fields that describe the class or type of information contained therein. More …More … A file management system Permits the user to create and define new databases. Once the data structure is defined, information can be entered into the file.
Database management systems (3) Terminology Database organization tools Permits the user to add, retrieve, delete, sort and update records. The records can be rearranged in ascending or descending order according to one or more field. Reporting functions Permits the user to define and print reports based on the data in the database.
Modelling with databases When learners model phenomena with a DBMS, they are required to integrate and interrelate content in one or more matrices. Learners who are building databases organize information by identifying the underlying dimensions of content. The process of searching for information and creating the database can be a meaningful instructional activity. The activity includes: Decisions pertaining to appropriate content relationships, which fields are necessary, how large they should be and how they should be ordered. Searching for information in a systematic fashion in order to fill (populate) the database. Organising and integrating of content in a specific content domain.
Coaching modelling with databases (1) Databases are useful for supplementing the learning of concept-rich content. Databases are especially useful when comparing and contrasting different content. Databases allow learners to examine and explore the underlying structure of content. The ultimate goal is to enable a learner to independently analyze a new content domain in order to: Determine the appropriate data model. Search for information in texts, videos and other resources to populate the database. Use the database to create and answer queries about the information it contains. Terminology
Coaching modelling with databases (2) Steps when coaching modelling with databases. Step 1: Learners query a completed database. Use existing database to answer questions about the information contained in the database. Require from learners to search for information in the database or sort the database. Step 2: Learners populate existing data structures. Learners add records. Activity provides a model for searching and identifying of information. Step 3: Learners make a plan. Ask learners to build a database. Learners must answer following questions: What kind of information is required? What kind of structure is required?
Coaching modelling with databases (3) Step 4: Learners adapt existing data structures or design new data structures. Modify existing structure. Design a new database structure. Learners are modelling the organizational skills required to develop data structures. Step 5: Learners create and populate data structures. Create a new database structure and populate the database. Requires learners to identify information needs, build data structures, access information and populate the database.
Coaching modelling with databases (4) Step 6: Learners write difficult queries. Learners use multiple search criteria to answer questions. Require writing of Boolean searches using and, or and not. Learners think about relationships among information contained in the database. Step 7: Learners extrapolate from databases. Create new fields in existing databases to support other applications. Step 8: Learners reflect on the activity. Learners review their progress. They answer the following questions: What have we learned from the content? What have we learned about database construction and the representation of content?
Advantages and limitations of modelling with databases Advantages Learners are actively engaged (mentally) in constructing representations rather than reading. Learners are required to define the nature of the relationships between concepts and construct records and fields that map those relationships. Learners are exposed to a process of comparing concepts and relationships. Limitations Critics claim that database activities produce nothing more than a tabular summary of information that is commonly available in textbooks. Some teachers claim that database representations may confuse students.