30-11-2012, 12:03 PM
Information Systems
Information Systems.ppt (Size: 434 KB / Downloads: 36)
Introduction
Information and knowledge are so important that society can be divided up into two groups.
Information rich - you have access to:
many TV and radio channels
books, newspapers and journals
computers and the World Wide Web.
Information poor -
tend to not have access to the Web and probably find it difficult to access relevant books and journals.
If you are following this course you will probably be information rich.
We are going to examine the nature and uses of information by looking at:
Differences between Data and Information
Organisational Information Systems
Information Management Software
Implications of Information and Communications Technology.
Knowledge
Knowledge is gained from Information.
We gain knowledge from information and we use that information to make decisions.
Explicit knowledge is rules or processes or decisions that can be recorded either on paper or in an information system.
Tacit knowledge exists inside the minds of humans and is harder to record. It tends to be created from someone’s experiences, so again is a set of rules or experiences.
Metadata
Metadata can be thought of as data that describes data.
Examples
a data dictionary
the card index system used by libraries before computerisation, where each card told you the author, title and where to find the book
data about documents or files stored on the computer. The computer keeps a file on its hard disk where it records information about each and every file on the computer. This includes information such as when the file was created or modified; who created it; the size of the file; the file type it is. This master or directory file is an example of metadata.
Source – Internal
All organisations generate a substantial amount of internal information relating to their operation.
Examples of internal sources:
Marketing and sales information on performance, revenues, market share, distribution channels, etc.
Production and operational information on assets, quality, standards, etc.
Financial information on profits, costs, margins, cash flows, investments, etc.
Internal documentation such as order forms, invoices, credit notes, procedural manuals.
Expert Systems
An expert system is a computer program that tries to emulate human reasoning. It does this by combining the knowledge of human experts and then, following a set of rules, draws inferences.
An expert system is made up of three parts:
A knowledge base stores all of the facts, rules and information needed to represent the knowledge of the expert.
An inference engine interprets the rules and facts to find solutions to user queries.
A user interface allows new knowledge to be entered and the system queried.
Expert systems are used for the following purposes:
To store information in an active form as organisational memory.
To create a mechanism that is not subject to human feelings, such as fatigue and worry.
To generate solutions to specific problems that are too substantial and complex to be analysed by human beings in a short period of time.