Information Processing.pdf

Information Processing Presenter: Miss Simpson  Objectives distinguish between data and information evaluate the reliability of information obtained from online sources differentiate between validation and verification of data identify a...

Information Processing Presenter: Miss Simpson  Objectives distinguish between data and information evaluate the reliability of information obtained from online sources differentiate between validation and verification of data identify appropriate validation and verification checks given a particular scenario  Concept Map Information Processing Information & File Organization data Evaluating online data Choosing a file access method verification & sources of data validation how data file access how files are methods is stored stored methods of serial file access types of verification sequential file document access random file methods of access direct file access validation Information and Data  DATA Data is raw, unprocessed facts. This may be facts about persons, places, things or events that have been collected through observation or measurement.  INFORMATION Information is meaningful knowledge derived from raw data. Data that has been processed, organised or put into context so that it is meaningful to the user may be regarded as information.  SOURCES OF DATA AND INFORMATION People Places Things  Cloud storage Cloud storage is a model in which data is stored on remote servers and can be accessed only via the Internet or cloud. Cloud storage is still hardware, usually hard disk drives. The difference between local storage and cloud storage is that local storage is physically connected to your computer system.  Cloud storage Cloud storage can be anywhere in the world and is indirectly connected to the computer hardware via a computer network, usually the Internet. Cloud storage services allow users to edit, save, synchronise, collaborate and share data via an Internet connection. Some popular applications such as Dropbox, Google Apps and Office 365 make extensive use of cloud storage. Cloud storage is deemed to be quite secure, provided users set up their accounts correctly and take the necessary precautions with their access credentials (username, password, and any other tokens/pass codes that may be provided)  Local storage Local storage is any physical storage device directly connected, internally or externally, to the computer system hardware. Types of document  Source Document A source document is a document that contains data for input into an information processing system. Document types used to collect, store and share data Document Human-readable document Machine-readable document  Document A document is printed or written, is usually paper-based, and is used to collect, store and share data. Documents may be generated by hand or by a machine such as a computer printer. Some documents may be read and processed by humans whereas others are read and processed by machines.  Human-readable Document A human-readable document is a document that may be read by a human but may not be in a form that a computer can automatically accept as input. An example is a handwritten list of vehicle parts. Machine-readable Document A machine-readable document is a document that can be read directly and understood by computer systems. Examples are documents that include barcodes and QR (scan) codes. QR codes are like barcodes but are made up of small black and white squares instead of lines. Some documents can be both human-readable and machine-readable, for example a product label that contains text about the item and a barcode to identify the item. Turnaround Document A turnaround document is a printed document that has been output from a computer system and that contains machine-readable objects that will allow the same document to subsequently provide input to a computer system. A turnaround document helps an organisation to increase efficiency by reducing the time it takes for data entry and helping to minimise and eliminate data entry errors. Remember that hard copy is permanent printed output from the computer.  Hardcopy A hardcopy refers to a physical, tangible, and printed or written document.  Softcopy A soft copy, on the other hand, refers to a digital or electronic version of a document or data.  QUESTIONS The difference between hardcopy and softcopy document The difference between data and information State ONE difference and ONE similarity between a machine-readable document and a human-readable document. Reliability of information obtained from online sources Reliability is the degree or extent to which the content of the information can be depended on to be accurate. Reliability has four characteristics: Characteristic Meaning Authenticity the information is real or true Lack of bias the information has been judged fairly and is not influenced by personal opinions Currency the information has the quality of belonging to the present time and is not out of date Relevance the information is connected or appropriate to its use  Microfilm Microfilm is often used as an alternative to the printer. The output is ‘printed’ on a roll of film (computer output microfilm) or sheet of film (computer output microfiche) rather than paper. In addition to being faster, this method also condenses large stacks of paper. Differentiate between verification and validation In many situations data is collected on forms, which means that the data is in a human-readable format. In order to be processed by a computer, data needs to be input into the computer system. This may be done manually by a data entry clerk typing the data on a keyboard or by use of a data capture device such as a scanner or optical character recognition (OCR) device. Humans are prone to making mistakes, measures must be put in place to identify and correct errors that may have been introduced during the data entry processes. A variety of verification and validation checks are used to identify and correct a number of errors that may occur. Verification Verification is a process during which data that has already been input or captured is checked to ensure that it matches the data on the source document. Good verification significantly reduces the number of typographical and transposition errors that occur during data entry  Typographical Error A typographical error is a typing error that affects the text, such as missing or additional characters. Examples are Guyyana and Britsh Virgins Islanbs.  Transposition Error A transposition error is one caused by switching the position of two adjacent characters in a number or text string. Examples are typing $5,450 instead of $5,540 or Gyuana instead of Guyana. Method of Verification  Double Entry One way to guarantee that the data entered matches the source data is a procedure called double (data) entry. Data is entered twice using a program that checks each second entry against the first. For example, some applications require users to enter their password twice. The application compares the two passwords to confirm that they are the same. In other applications where there is more data to be entered, the program produces a list with the pairs of data that do not match so that the correct values can be re-entered.  Proofreading Proofreading is the process of checking a document for any kind of grammatical, typographical, or formatting errors. Proofreading should always be the last step taken before a document is published online, handed in to a professor, submitted for a job application, or otherwise shared with its intended audience. Method of Validation  Validation Validation is a checking process in a program which is aimed at finding out if the data is genuine. Validation ensures that data entered into a database form, web form or computer program conforms to a set of validation rules and may include a presence check to check whether the data is present, or a range check, for example to ensure that the data is between 1 and 100. Any data that is invalid is rejected by the validation process and must be corrected before the data is accepted.  Range Check Range check ensures that the data entered is within a certain range. For example, when you enter a number corresponding to a month of the year, the acceptable numbers is 1 to 12. range of acceptable numbers 1 to 12  Reasonable Check This check tests whether the data obeys specified criteria. For example, the age of a child at preschool could be about 4 years old, but not 14 years. Reasonableness checks are therefore used to detect doubtful data.  Data type Check This is also known as a character or alphanumeric check. When a database is created, each field will accept a specific type of data. Whenever data is entered into a field the database will check that it is of the correct type, for example alphabetic or numeric. If it is not, then an error message will be displayed, and the data will have to be re-entered.  Consistency Check A consistency check compares the contents of two or more fields to make sure that they make sense. It is also called an inconsistency check, since it mostly identifies errors and discrepancies in the data. This check compares new data with previously entered data. For example, checking that the age entered corresponds to the age calculation from the date of birth.  Presence Check This type of check ensures that the data is actually entered. It can be used on any field in a database. For example, every person in a particular database must be assigned to a department. Therefore, a presence check on each employee's record could ensure that a department is entered in the form.  Length Check This check verifies that the data entered is the correct length. For example, a password for a credit card may be four digits long, therefore entering three or five digits may result in an error. (Example: year of birth must be four digits, e.g. 2004.)  Format Check Format Check does the data conform to the format required? (Example: date must be in the format dd/mm/yyyy.)  Reference Scribendi- https://www.scribendi.com/academy/articles/what_is_proofreading.en.html Information Technology CSEC Third Edition Textbook Heinemann Information Technology for Csec https://www.youtube.com/watch?v=yFSEf6TOzDQ Information Technology for CSEC Examination Third Edition by Howard Campbell & Alan Wood