Our century designate an information age. Information is the unique capital which is multiplied if it shares with others. In the free democratic society the person has almost unlimited access to any information.
All phenomena in the nature and society are learned on the basis of information. Word «information» means clarification, presentation, notification. The concept «information» doesn't exist out of concept of system; information is the reflection in consciousness of people of objective causes and effect relationships in the real world surrounding us. Academician A.Berg figuratively noted that the term «information» has no exact determination, just as it has no exact determination and «time», but people perfectly measure.
Information is any message, transmission of data that the specific phenomenon or a set of the phenomena came or will come. Let's say you hold the document made in an unknown language to you. You can evaluate the quality of paper, ink, handwriting, but can't gather information necessary for you. You don't know language. Language in this case is a method of processing of the data received by you.
Information is a product of interaction of data and the methods considered in a context of this interaction.
There are registered signals. The informatics doesn't study the nature of signals – it is the fact of their registration interests. Data are an information representation in a form suitable to automate its collection, storage and later processing on the computer.
Knowledge – the facts, messages on environment (data domain), procedures and rules of handling the facts, and also information when it is necessary to apply rules and procedures. Knowledge – the results of knowledge of activities checked by practice, more precisely, its displays in thoughts of the person. There was a problem of representation of knowledge in memory of the machine with the appearance of calculating machines; there was the problem of access to them, additions and changes of knowledge. The central problem is representation of knowledge. In a general view to memories of knowledge are represented in the form of any sign system.
Information is classified depending on a control object and assignment on the following classes (fig. 1.2)
Fig. 1.2 – Information classification
Properties of information:
•Adequacy – a level of compliance of information received by a customer to the fact that the author enclosed in its contents (i.e. data)
•Accuracy is a level of compliance of information to the present situation of time. Quite often with urgency, as well as with completeness, connect commercial informative value. As information processes are expanded in time, authentic and adequate, the out-of-date information can make erratic decisions
•Reliability – compliance of objective reality (both current and passed) world around. Reliability of information is measured by confidential probability of necessary accuracy, i.e. probability of that the parameter value displayed by information differs from the true value of this parameter in necessary accuracy.
•A completeness of information – sufficiency for decision-making. It depends both on a completeness of data, and on existence of necessary methods
•The urgency is a level of compliance of information to the present situation of time. Quite often with urgency, as well as with completeness, connect commercial informative value. As information processes are expanded in time, authentic and adequate, the out-of-date information can lead to erratic decisions
•Stability of information is an ability to react to changes of basic data without violation of necessary accuracy. Stability of information, as well as representativeness is caused by the selected technique of its selection and formation.
Timeliness of information means its availability in advance not later than the assigned moment of time, coordinated with the time of solution of the objective
• Redundancy of information (the literal text redundancy of 20-20 %, visual information more than 90 %, video information has till 98-99)
• Objectivity and subjectivity of information
• Accessibility of information – a measure of possibility to receive this or that information. A level of accessibility of information is influenced by the data accessibility