Information quality (Wand & Wang)
is conceptualized as fitness for use for specific purposes.
Information quality is evaluated in which dimensions? (4)
- Accuracy
- Reliability / consistency
- Timeliness (currency)
- Completeness
IQ: accuracy means?
Data represents the correct state of the real world.
example: Ashley and John have written a test. If we enter Ashley’s mark for John in the system, the mapping would be inaccurate.
IQ: Reliability means?
Dependability of the output information, or correctness of the analyzed data.
IQ: Timeliness (currency) means?
Whether the data is up-to-data, and available on time.
IQ: completeness means?
Ability of the information system to represent every relevant state of the real world system.
What are the three data abstraction levels
- Conceptual level: used for understanding and communication
- Logical level: how to structure data so that it becomes suitable
- Physical level: how data is stored and transmitted
Classification
An abstraction mechanism used to represent phenomena with common properties.
Pre-defined classification (2)
Pre-defined:
- Reasons about the data using definitions provided by the data designer
- Assumes one correct classification scheme
Non-classified classification (2)
- Data instances and their properties stored without pre-defined classification.
- Users define their own classifications based on properties of interest and demand.
Resource description framework (RDF)
Store instances (things) and their properties
