CIS Information and Databases 1 Information and Databases

CIS Information and Databases 2 Data Modeling: Documenting Information Architecture Information Architecture - a conceptualization of how the information requirements are met by the system. From the user’s viewpoint: –What information is in the system? –How is the information organized? –How can users obtain whatever information they need?

CIS Information and Databases 3 Entity Relationship Diagrams What kinds of things does the system collect information about? –entities What is the relationship between these entities? –Relationship or association among entities What specific information does it collect about each of those things? –attributes

CIS Information and Databases 4 Entity-relationship diagram for part of a university registration system

CIS Information and Databases 5 Types of relationships in entity-relationship

CIS Information and Databases 6 Possible Attributes for the Entity Types DEPARTMENT Department identifier College Department head Scheduling coordinator COURSE Course number Department Required of department major (y/n) Course description SECTION Section identification number Semester Year Classroom Start time End time Days of week for class meetings PROFESSOR Employee identification number Name Address Birthdate Office telephone Social Security number STUDENT Student identification number Name Address Birthdate Telephone Gender Ethic group Social Security number OFFICE Office number Building Telephone extension

CIS Information and Databases 7 Use of E-R Diagrams E-R Diagrams are actually used for the non- technical purpose of identifying the types of things within the system’s scope and the relationships among these types of things.

CIS Information and Databases 8 Types of Data in Today’s Information systems Pre-defined Data - numerical or text items whose meaning are specified explicitly. Text - letters, numbers, and other characters where the meaning is not pre-defined. Images - data in the form of pictures Audio - data in the form of sound Video - combination of pictures and sound displayed over time. Future types: taste and smell?

CIS Information and Databases 9 Images produced by information systems

CIS Information and Databases 10 Review of Some Database Concepts What is a database? Database management system Logical vs. physical views of data files, records, fields, keys relational databases normalization SQL Push vs. Pull systems. Pre-programmed vs. ad-hoc

CIS Information and Databases 11 Some new Data base Concepts Multi-dimensional databases: –most relational database models are optimized to support transaction processing. –Business professionals often wish to analyze large amounts of data frequently, e.g. along dimensions of product, time period, and store. –There is a significant difference between transaction processing vs. analytical processing. –Multi-dimensional databases help support data warehouses which we will discuss further later in the semester.

CIS Information and Databases 12 Multi-dimensional Databases Transaction Systems: –Insert an order for 300 baseballs –Update this passenger’s airline reservation. –close-out accounts payable records for this vendor. –What is the current checking account balance for this customer? Analytical Support Systems: –Did the sales promotion last quarter do better than the same promotion last year? –Is the five-day moving average for this security leading or trailing actual prices? –Which product line sells best in middle-America and how does this correlate to demographic data.

CIS Information and Databases 13 A Multidimensional database

CIS Information and Databases 14 Geographic Information Systems Organizing data so that it can be accessed by pointing at a region on a map. Based on spatial or geographic coordinates. Marketing and planning applications can visualize customers The important distinction between GIS and other types of information systems is not in the database, but in the access method (i.e. through maps).

CIS Information and Databases 15 A geographical information system

CIS Information and Databases 16 Some Information Concepts Data: Unorganized facts and figures. (raw material) Information: Data that has been processed into a form that is meaningful to the recipient and is of real of perceived value in current or prospective actions or decisions. Information: –adds to a representation –corrects or confirms previous information –has “surprise” value in that it tells us something we did not know, or could not predict. –What is a “finished product” to one, may be “raw materials” to someone else.

CIS Information and Databases 17 Definitions: Information vs. Knowledge Knowledge: a combination of instincts, ideas, rules, and procedures that guide actions and decisions. Helping to provide the best available knowledge to decision-making is another role of information systems

CIS Information and Databases 18 Relationship Between Data, Information, and Knowledge The difference between data and information is easy to remember. It is often cited as the reason why systems that collect large amounts of information fail to meet management’s information needs. There are many methods of converting data into information for decision making. Managers take action based on information about a current situation plus their accumulated knowledge. Actions taken feed the process of accumulating more knowledge (experience). Example: How do medical students become competent physicians?

CIS Information and Databases 19 Relationship Between Data, Information, and Knowledge

CIS Information and Databases 20 Attributes of Quality Information Timeliness Completeness Conciseness Relevance Accuracy Precision Appropriateness of Form

CIS Information and Databases 21 Special Characteristics of Information Usefulness - depends on combination of quality,accessibility,and presentation. One person’s information may be another person’s noise. Soft data may be as important as hard data. Ownership of information may be hard to maintain. More information is not always better (information overload). Politics can often hide or distort information.

CIS Information and Databases 22 Review: Information Needs - Operational vs. Strategic Time frame - historical vs. predictive for the future Currency - highly current vs. can be quite old Expectation - anticipated vs. surprise Source - largely internal vs. largely external Scope - well-defined, narrow vs. very wide Level of aggregation - detail vs. summary Frequency - real-time vs. periodic Organization - highly structured vs. loosely structured Precision - highly precise vs. not overly precise

CIS Information and Databases 23 Question? What special attributes or characteristics of information have affected you as an individual or as part of a group?

CIS Information and Databases 24 Determinants of Information Usefulness and Related Roles of Information Systems INFORMATION QUALITY ACCURACY PRECISION COMPLETENESS AGE TIMELINESS SOURCE

CIS Information and Databases 25 Determinants of Information Usefulness and Related Roles of Information Systems INFORMATION ACCESSIBILITY AVAILABILITY ADMISSIBILITY INFORMATION PRESENTATION LEVEL OF SUMMARIZATION FORMAT INFORMATION SECURITY ACCESS RESTRICTION ENCRYPTION

CIS Information and Databases 26 Do managers expect the truth?