【正文】 o the subdivision and make online inquiries as and when necessary. 。 Morton, 1978). The term database may refer to any collection of data that might serve an organizational unit. A database on a given subject is a collection of data on that subject that observes three criteria: prehensiveness (pleteness), nonredundancy, and appropriate structure. Comprehensiveness means that all the data about the subject are actually present in the database. Nonredundancy means that each individual piece of data exists only once in the database. Appropriate structure means that the data are stored in such a way as to minimize the cost of expected processing and storage (Awad amp。 Riley, 1994). Information as an Aid to Decision Making Simon (1977) describes the process of decision making as prising four steps: intelligence, design, choice, and review. The intelligence stage enpasses collection, classification, processing, and presentation of data relating to the organization and its environment. This is necessary to identify situations calling for decision. During the decision stage, the decision maker outlines alternative solutions, each of which involves a set of actions to be taken. The data gathered during the intelligence stage are now used by statistical and other models to forecast possible outes for each alternative. Each alternative can also be examined for technological, behavioural, and economic feasibility. In the choice stage, the decision maker must select one of the alternatives that will best contribute to the goals of the organization. Past choices can be subjected to review during implementation and monitoring to enable the manager to learn from mistakes. Information plays an important role in all four stages of the decision process. Classification of Management Information Systems There are various types of management information systems. Mason and Swanson (1981) describe four categories of management information systems: (1) databank information system, (2) predictive information system, (3) decisionmaking information system, and (4) decisiontaking information system. The classification is based on the level of support that the information system provides in the process of decision making. Sachdeva (1990) prehensively presents these four types of systems: Databank Information System. The responsibility of this information system is to observe, classify, and store any item of data which might be potentially useful to the decision maker. Predictive Information System. This system moves beyond pure data collection and the determination of trends over time. Predictive information systems provide for the drawing of inferences and predictions that are relevant to decision making. If data from the above examples were to be used in this way, it is possible to obtain information useful for making predictions or for drawing inferences. DecisionMaking Information System. This system goes one step further in the process of decision making and incorporates the value system of the organization or its criteria for choosing among alternatives. An extension organization39。 McLeod, 1995). Basic concepts Data versus Information Data refers to raw, unevaluated facts, figures, symbols, objects, events, etc. Data may be a collection of facts lying in storage, like a telephone directory or census records. Information is data that have been put into a meaningful and useful context and municated to a recipient who uses it to make decisions. Information involves the munication and reception of intelligence or knowledge. It appraises and notifies, surprises and stimulates, reduces uncertainty, reveals additional alternatives or helps eliminate irrelevant or poor ones, and influences individuals and stimulates them to action. An element of data may constitute information in a specific context。s ponents together and provides for better operation and survival in a petitive environment. The term information system usually a puterbased system, one that is designed to support the operations, management, and decision functions of an organization. Information systems in organization