Production of useful information, usually in the form of documents and reports

• Data integrity refers to the accuracy and completeness of data entered in a computer or received from the information system. Integrity is measured in terms of accuracy, timeliness and relevance of data.

• Accuracy
• It refers to how close an approximation is to an actual value. As long as the correct instructions and data are entered, computers produce accurate results efficiently. In numbers, the accuracy of a real number depends on the number. For example, 72.1264 is more accurate than 72.13.

• Timeliness
• This is the relative accuracy of data in respect to the current state of affairs for which it is needed.
• This is important because data and information have a time value attached to them. If received late, the information may have become useless to the user. For example, information in the newspaper that is meant to invite people for a meeting or occasion must be printed prior to the event and not later.

• Relevance
• Data entered into the computer must be relevant so as to get the expected output. In this case, relevance means that the data entered must be pertinent to the processing needs at hand and must meet the requirements of the processing cycle. The user also needs relevant information for daily operations or decision making.

Threat to data integrity

• Threats to data integrity can be minimized through the following ways:
• Backup data preferably on external storage media.
• Control access to data by enforcing security measures.
• Design user interfaces that minimize chances of invalid data entry.
• Using error detection and correction software when transmitting data
• Using devices that directly capture data from the source such as bar code readers, digital cameras, and optical scanners.

• As mentioned earlier, data can be processed manually, mechanically and electronically.

1. Manual data processing

• In manual data processing, most tasks are done manually with a pen and a paper. For example in a busy office, incoming tasks (input) are stacked in the “tray” (output). The processing of each task involves a person using the brain in order to respond to queries.
• The processed information from the out tray is then distributed to the people who need it or stored in a file cabinet.

1. Mechanical data processing

• Manual is cumbersome and boring especially repetitive tasks. Mechanical devices were developed to help in automation of manual tasks. Examples of mechanical devices include the typewriter, printing press, and weaving looms. Initially, these devices did not have electronic intelligence.

1. Electronic data processing

• For a long time, scientists have researched on how to develop machine or devices that would stimulate some form of human intelligence during data and information processing. This was made possible to some extent with the development of electronic programmable devices such as computers.
• The advent of microprocessor technology has greatly enhanced data processing efficiency and capability. Some of the micro processor controlled devices include computers, cellular(mobile) phones, calculators, fuel pumps, modern television sets, washing machines etc

• A file can be defined as a collection of related records that give a complete set of information about a certain item or entity. A file can be stored manually in a file cabinet or electronically in computer storage devices.
• Computerized storage offers a much better way of holding information than the manual filing system which heavily relies on the concept of the file cabinet.

• Some of the advantages of computerized filing system include:

1. information takes up much less space than the manual filing
2. it is much easier to update or modify information
3. it offers faster access and retrieval of data
4. It enhances data integrity and reduces duplication
5. It enhances security of data if proper care is taken to secure it.

Elements of computer file

• A computer file is made up of three elements: characters, fields and records.

• Characters
• A character is the smallest element in a computer file and refers to letter, number or symbol that can be entered, stored and output by a computer. A character is made up of seven or eight bits depending on the character coding scheme used.

• Field
• A field is a single character or collection of characters that represents a single piece of data. For example, the student’s admission number is an example of a field.

• Records
• A record is a collection of related fields that Represents a single entities, e.g. in a class score sheet, detail of each student in a row such as admission number, name, total marks and position make up a record.

Logical and physical files

• Computer files are classified as either physical or logical

• Logical files
• A computer file is referred to as logical file if it is viewed in terms of what data item it contains and details of what processing operations may be performed on the data items. It does not have implementation specific information like field, data types, size and file type.

• Physical files
• As opposed to a logical file, a physical file is viewed in terms of how data is stored on a storage media and how the processing operations are made possible. Physical files have implementation specific details such as characters per field and data type for each field.

• There are numerous types of files used for storing data needed for processing, reference or back up. The main common types of processing files include

• Master files,
• Transaction,
• Reference,
• Backup, report and
• Sort file.

1. Master file

• A master file is the main that contains relatively permanent records about particular items or entries. For example a customer file will contain details of a customer such as customer ID, name and contact address.

1. Transaction (movement) file

A transaction file is used to hold data during transaction processing. The file is later used to update the master file and audit daily, weekly or monthly transactions. For example in a busy supermarket, daily sales are recorded on a transaction file and later used to update the stock file. The file is also used by the management to check on the daily or periodic transactions.

Reference file

A reference file is mainly used for reference or look-up purposes. Look-up information is that information that is stored in a separate file but is required during processing. For example, in a point of sale terminal, the item code entered either manually or using a barcode reader looks up the item description and price from a reference file stored on a storage device.

Backup file

A backup files is used to hold copies (backups) of data or information from the computers fixed storage (hard disk). Since a file held on the hard disk may be corrupted, lost or changed accidentally, it is necessary to keep copies of the recently updated files. Incase of the hard disk failure, a backup file can be used to reconstruct the original file.

Is the production of useful information usually in the form of documents and reports?

Is information from the system that is used to make changes to input or processing activities?

Which of the following is a set of interrelated components that collect manipulate store and disseminate data and information?

What is information system quizlet?