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Creado por alexxlauren
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ICT Theory Revision Guide 3.1.1 Data, Information, Knowledge and Processing a) Data is the raw facts and figures (alphanumeric characters), without meaning. For example, 211210 is the data entered in when entering the date 21/12/2010. b) Information is processed data with a meaning (and sometimes context and structure): Information = Data + [Context] + [Structure] + Meaning c) Representation Advantages Disadvantages Text · Clear to understand · Lots of detail · Need to be able to read · Need to understand language · Can be confusing – level of language · Lots of text cannot be read quickly – road signs Graphics · Multilingual – do not need language to understand · Can match what you see – physical shapes · Can be confusing if you don’t know the symbols – road signs · Some symbols mean different things in different cultures and countries Sound · No fixed position · No line of site required · Good for visually impaired people · No good in large areas – distortion of sound · Usually language based · May not know the sound · Need to be able to hear Moving pictures · Lots of information conveyed · Not language dependent · Can exemplify text · Linear – if you do not see the beginning you may not understand · Problems if sound LED · Can allow data to be kept secure · Can be used in noisy places · Similar to graphics · Need to be able to see the lights · Combinations of lights may need to be known to be understood d) Information is processed data with a meaning, structure and context. Knowledge is the application of that information to a situation. e) Data type Description Boolean · Can contain one of only two values, e.g. male/female, true/false Real · Contains numbers which will have decimal places Integer · Contains whole numbers with no decimal places Text/string · Any alphanumeric character, including numbers, text and symbols, e.g. 12345, £$%^&, Hello Date/time · Contains numbers and letters (depending on format) displaying the date/time to different degrees of accuracy f) Direct (primary) data is data collected from an original source. It is data that has been physically collected by you. Indirect (secondary) data has two interpretations: - Data that has been used for a purpose different to that for which it was originally collected. - The people/companies involved in collecting the data are different to those using the data. For example, market research companies. Advantages Disadvantages Direct · The source and collection method is known and verified. · The exact data required can be collected. · Can change the data being collected in response to answers. · May not get a large range of data. · Data may not be available – location/time. Indirect · Large range of data available that could not have been collected directly. · Data can be available from different locations and time periods. · Analysis might already have been completed on some of the data. · Do not know if any bias was placed on the collection. · Cannot be certain of accuracy of the recording of data. · May not have all the information about how, when and where it was collected to make a valued opinion on its usefulness. · If the information was not originally collected, may not be able to get hold of it. g) A static information source is one where the data, once created, does not change. For example, books and CDs. A dynamic information source is one where the data can change and be updated. For example, pages on the World Wide Web and CD-RW. Static (e.g. CD-ROM) Dynamic (e.g. Websites) There is a limited amount of information available. The WWW provides a large volume of information. Does not require Internet access. Only people with Internet access can access the information. More reliable source of information. The information is not always reliable. Does require a suitable computer with a CD-ROM drive. You do not need a CD-ROM drive or a computer – can access using a mobile phone. Data cannot be updated very quickly. Data can be updated very quickly. The CD can be scratched/broken or lost/stolen. Internet access might not be working. Difficulty accessing the pages. Software to search the data on the CD can be included with the CD along with any additional necessary software. The user may not have the correct browser software. If there are errors, correction notices would have to be sent out to people. The WWW provides many different opinions. There is a cost involved in making and sending the CD-ROMs. Can potentially reach everybody. A required CD-ROM can take time to arrive. People come to a website rather than the CD-ROM being sent to a person. Several CD-ROMs may need to be looked at to find the required information. Hyperlinks can lead the individual to related sites. The CD-ROM is in a single location – have to possess it to look at it. The same WWW resource can be accessed from anywhere as long as the address is known. h) To understand what the quality of information produced will be like, we must determine how good the data entered is. This depends on six factors: Factor Description Completeness · Information must be whole in order to understand (must have context, structure and meaning) Accuracy · Data needs to be accurate. If it’s not, you can’t rely on the information it provides Relevance · Information must be relevant. If it does not relate to the topic, it’s worthless Presentation · Information must be presented so that we can understand and find what is needed (different methods includes pictures, graphs and text) Age · Information might be too old (it can change over time, so may not have the same relevance it once did) Level of detail · Enough (and not too much) information must be given i) Encoding data is taking the original data and storing it in a different representation. Advantages Disadvantages · Less memory requirement · Improved security · Increased speed of input · Data can be validated · Organisation of data · Precision of data coarsened · Encoding of value judgements is distorted · User needs to know the codes used · Limited number of codes · Difficult to track errors j) Validation ensures that the data value entered is sensible and reasonable (doesn’t check if it’s accurate). Range Check - to check that the value entered is within a pre-determined range. Type Check - makes sure that the data is of the correct data type. Check Digit - allows a number to be self checking – the computer applies a set of rules which determines of the numbers entered are valid. (ISBN) Field Length Check - checks the number of characters entered (minimum and maximum) Field Presence Check - makes sure data has been entered into a field Lookup Check – takes the value entered and compares it against a list of values in a separate table Picture/Format Check – makes sure the location of the numbers and letters in the data is the same every time (differs from a type check, which checks the overall type) k) Verification ensures that the data entered is entered correctly (reducing errors), but not that it is correct itself. Computer verification (double entry) - you enter the data in twice and the computer checks the entries. Manual verification (proof reading) - you enter the data in and check manually from the screen against the source. Lookup verification - having part of the data and retrieving the rest/checking the rest by looking up the data on a list (e.g. postcode) l) Back-up is keeping a copy of the current data. It is important so that data is not lost, so is written at short intervals. There are many different back-up devices, including: - external memory: floppy disk, memory card, etc. - external hard drive - tape - making a second copy on a different disk, storing it off site. Archiving is for long-term storage of data that is not required immediately, often at all. Archiving is written to large capacity storage devices at long intervals. The procedure for archiving files is: 1) Copy the file onto the archival media (disk or tape). 2) Verify the copied files (make sure the two copies are exactly the same and the copy has worked). 3) Delete the original files. m) Information costs time and money to be produced. Costs are incurred in four main areas – hardware, software, consumables and personnel. Hardware can be used to collect the information, process it and output it. The initial costs of the hardware are expensive. Ongoing costs include repair, maintenance, network management, etc. Software licenses need to be purchased, including operating systems, utilities, etc. There may also be training costs to train users how to use the software. Consumables are items that get used, including paper and printer ink/toner. Personnel costs are the costs related to people working in the organisation. n) PROCESSING Action performed on the data OUTPUT Outputting information that is in the system STORAGE Data is held Feedback Feedback is where the output from the system forms part of the input to the system. 3.1.2 Software and Hardware Components of an Information System a) Hardware is the physical components that make up a computer (e.g. graphics cards and speakers). Software is the programming code that makes the computer work (e.g. applications and operating systems). Standardisation is the imposition of a set of standards on manufacturers. It affects web pages (page may be displayed differently), company takeovers (lack of global standards means the two systems can’t work together), and ICT manufacturers (allows them to release new hardware and make more money). Disadvantages: Cost If you purchase a computer that is not part of a global standard then all the subsequent upgrades and parts you buy will have to come form specific sources and are likely to be very expensive. If you do not buy items that are compatible with your computer, then they may not work correctly, or at all. Availability If there is limited availability for a piece of hardware then the supply itself may be limited. Limited supply has a knock-on adverse effect on cost. Technical Support If availability is limited, then the support for it is also likely to be limited and expensive. b) Input devices needed for different situations include: - Touch screen - OMR (optical mark reader) - OCR (optical character recognition) - Bar code reader - Magnetic strip - Chip and pin - Biometrics - Keyboard - Mouse - Microphone - Sensors Output devices needed for different situations include: - Monitor - Laser printer - Inkjet printer - Impact printer - Plotter - Speakers - Motors Storage devices needed for different situations include: - Hard disk - Floppy disc - Zip disc - CD-R - CD-RW - DVD - Magnetic tape - Flash drive c) Visually impaired specialist hardware: - a Braille keyboard - a microphone (used with voice recognition software) - a loudspeaker (text read out) - a Braille printer (impact printer that can create Braille on a page) Motor impaired specialist hardware: - a mouth stick - a puff-suck switch - an eye-typer (fits onto muscles around eye to control pointer) - a foot mouse d) Specialist software for physically impaired: - Text-to-speech system - Speech-to-text system - Auditory feedback system (plays sounds in response to user activity, e.g. pop-up) - Screen magnifier - Predictive text - Sticky keys (allows keys to be pressed once and system act as if it was being held down) e) Types of software include: Operating systems: - software that controls the allocation and use of hardware resources, such as memory, hard disk space, peripheral devices - performs basic data management tasks, such as recognising input from the keyboard User interfaces: - this is the means by which the user can interact with an application or operating system - a GUI (graphical user interface) is based on graphics and pictures rather than text - a WIMP (Windows Icons Mouse Pointer) is a type of GUI Utilities: - these are additional programs to make the use of the computer easier - they monitor and maintain the computer system, such as virus checkers, and printer monitoring software Applications software: - programs which solve particular problems and replace manual methods - includes word processors, databases, spreadsheets, email, etc. f) Command line interface: - types commands at a prompt with usage of switches - low memory overheads - specialist knowledge required Forms: - structures areas for responses - validated - logical Menus: - drop-down boxes/pop-up boxes - structured and categorised - can be cascaded - context sensitive – different set of menus depending on what you’re doing Natural language: - written or spoken everyday language - tablet PCs for written; voice recognition for spoken - computer translates into commands needed to operate3.1.3 Software and Hardware Components of an Information System a) Standard software includes: - word processor (letters, memos, reports) - desktop publishing (flyers, brochures, posters, business cards) - spreadsheet (mathematical models, financial records, forecasting) - database (user systems, web pages, data handling, sorting, searching) - web authoring (websites) - presentation (kiosk shows, aiding speeches) b) School administration systems: - a database to hold records (storing student details, each pupils’ UPN, etc.) - a facility to record attendance (monitoring students absences, etc.) - a facility to record student marks (storing data about students’ grades, etc.) Stock control systems: - a spreadsheet or database to have a list of all stock items and their suppliers - a record of minimum and maximum stock levels - have links to order databases to automatically order stock - predict stock requirements based on previous sales Booking systems: - allow users to select times and dates - check availability of certain events - confirmation and payment Online training systems: - use of video clips as demonstrations - step by step features - statistical information can be available - help screens can be made Route-finders: - specify the location you are leaving from and going to - specify places and roads you want to pass through - specify type of journey - save and print a route in a number of formats, for example text and maps Customer records systems: - store customer contact details - have unique IDs for each customer - store orders against customers - generate order histories along with invoices c) Macros: A macro is a sequence of instructions defined as a single element. - run as a single action - macro can call another macro - can make use of variables and parameters - can be attached to an element (button, run by event, etc.) - can interact with the user Advantages Disadvantages - a repetitive task can be performed using a simple instruction (e.g. button, mouse click) - errors may be reduced as instructions in the macro are the same every time and run automatically - inexperienced users can perform complex tasks by using a pre-recorded macro - errors may occur if the conditions when the macro was recorded was different - users must know and remember the key combination to run the macro - inflexible – the macro may not do precisely what the user wants - if the macro is run from a different starting point than intended then it may go wrong - to correct any errors the user must have some knowledge of how the macro was recorded Wizards: A wizard facility helps the user to produce the final product. - allows the user to go back steps if required - interacts with the user to produce the final product step by step Advantages Disadvantages - allows for house style to be applied - ensures that nothing is left out - can reduce time creating a document - limited to the template - if changed only changes subsequent documents - an error in the template will be carried through to all documents Templates: A template provides standard pre-set layouts and formats. - character formatting (font size, colour, type of font, etc.) - page formatting (margins, size, layout, etc.) - text insert (standard words, data, time, etc.) - graphics inserts (standard logo, position, etc.) Advantages Disadvantages - allows for house style to be applied - ensures that nothing is left out - can reduce time creating a document - limited to the template - if changed only changes subsequent documents - an error in the template will be carried through to all documents Styles: A style is similar to a template, and is used to set out the layout of the page. - All documents conform to a layout, but with scope for creativity by the producer Advantages Disadvantages - documents and other material are produced to a consistent house style - different people can work on different parts of a document whilst keeping consistency - someone needs to develop the style before it can be set as a template d) Data-entry screens can be tailored to meet the needs of the end-user: - consistent layouts should be used (following the house style) - text should be easily readable, chosen for clarity - graphics/animation should be used to meet the needs of the users - images should be fit for purpose, and kept to a minimum - help messages should be useful and clear - information should be in a logical order - interface should be easy to learn and use (minimising training) - commonly used functions (back, search, sort, etc.) should be given a button/shortcut - expertise of the user must be considered Considerations for forms: - Consistency (menus, buttons, formats, etc. Should be consistent) - Relevance (information should be concise requiring minimum input from user) - Supportiveness (user doesn’t want too much information, but enough to help them through the data entry) - Visual and audible cues (needs to be feedback to confirm actions – e.g. a green/red tick next to a correct/incorrect password) e) Buttons - to take the user to a specified page - to run a selected action/command - to run a macro - to display text Forms - to assist in the entry of data - can provide assistance to users in the form of instructions and error messages - can include validation of data entered - form controls increase interactivity, and include:- button (to start an event/run a macro)- check box (user can tick an option)- group/frame (controls can be grouped together if their related)- option button (options can be selected)- text box (allows text to be written)- combo box (items can be selected from a drop-down box)- list box (gives a list of items)- image (a picture can be inserted)- label (instruction labels or titles can be added)- automatic fill-in box (fills in boxes automatically, e.g. address given the postcode) Menus - enables a user to select actions - three types of menu include:- full-screen menu- pop-up menu- pull-down menu f) There are benefits and problems with tailoring applications software: Benefits Problems - simplification of user data entry, leading to fewer mistakes - time taken to enter data can be reduced (using buttons, forms, macros and menus) - data entered can be validated - level of technical knowledge required to create interface is high - may take time to adapt the interface if needed - task cannot be completed if a problem occurs/option is not available g) House-style or corporate image refers to a company or organisation’s standard method of presentation of documents and other forms of communicating information. A house style is a set of rules followed on all documents sent out by a company or organisation to maintain a consistent appearance. Characteristics include: - having a logo - using templates and macros - having specific colour schemes, fonts and other layout features House styles ensure than information is less likely to be missed off from documents. h) A consistent house style can be maintained through the use of master documents/slides, style sheets and templates. Master Slide: A master slide enables a team of people to work on the same presentation separately. A master slide will show: - theme to be used for the presentation - position of any graphics to be shown on each slide in the presentation (e.g. a company logo) - position of any information which must appear on each slide, such as date, slide number and any footer/header text. The master slide can contain: - text formatting - object positioning - footer/header placeholders In word processing software, master documents can be used to set up a multipart document. By using a master document, a table of contents, index, references, footers and headers can be created within. Styles: Style sheets are similar to templates. They ensure all company documents are produced to a consistent house style, and enable different people to work on parts of the same documents with a consistent end result. However, they mean all documents end up looking exactly the same, and the company needs to pay for designers to develop the style. Templates: Templates provide pre-set layouts and formats, for example, - character formatting - page formatting - text insert - graphic inserts i) Output from different software providers is often saved in different formats. Different file types are suited to different applications. This means when users open a document with that file type, it will usually open the correct program associated to that type. Universally recognised file types: - txt and rtf (rich text format) for documents - CSV (comma separated values) and TSV (tab separated variable) for spreadsheets or tables of data - Dbf and CSV for databases Procedure for converting files to a different format: Open file in package A. Save as or export to the package B format (if not possible, format common to A and B) Open or import in package B and save. j) Different users of standard/generic applications software have different needs for that software. 3.1.4 Spreadsheet Concepts a) There are two main types of modelling – modelling of objects and mathematical modelling. Modelling of objects: - allows you to create a virtual representation of the item - can model large items and see the effect of different external influences (e.g. surface it’s on, natural disasters, etc.) - can see different layers of the model (e.g. the frame of a car, the wiring of a car, and the interior of a car) - model can be rotated/magnified to see different aspects of the item - questions can be asked –a component can be changed to see the effect it has (effects can be gauged on the model rather than risking building the real thing) Mathematical modelling: - based on a layout of rows and columns (spreadsheet) assisting in a logical format - replication of a cell horizontally/vertically (including formulae, with cell references being updated automatically) - can be based on functions and formulae (allowing variables to be edited and for automatic recalculation of any cell based on those variables) - “What if...?” questions can be asked (changing variables); goal seek can also be used - cells and ranges can be given specific names to reference (e.g. VAT_RATE for the cell containing the rate of VAT) - use of multiple different worksheets in the spreadsheet - use of graphs and graphical representation of data Modelling is used because: - it is less risky (safer and cheaper) to test a model of a design than to create it in reality and test it - only one model needs to be created on a computer; a real model would need to be recreated every time a different variable was changed – costing time and money - models can be backed up and shared - models can be sped up/slowed down to see effects in the short run/long run (not possible in reality) b) A model can recalculate values when numbers change, predict what will happen as an effect, and test different scenarios. There are four features involved in this. Variables: a variable is an identifier associated with a particular cell – within the cell, there will be a value Formulae: a formula is a calculation which uses numbers, addresses of cells and mathematical operators Rules: rules are a set of procedures that must be followed and can also be the sequence of events required for the calculation to work Functions: a function represents a complex formula that uses reserved words c) “What if...?” questions are an attempt to find out what will happen in the future. They require a value to be changed so that other values can be re-calculated. The advantages of being able to do this include: - re-calculation – the model can be changed many times with many different values and figures analysed - reduced cost and time – creating physical models to answer “What if...?” questions would require a new model to be created for each question d) A spreadsheet is made up of different parts. Worksheets: a worksheet is a large grid of cells on a single sheet. It can be used to hold data on a single area of the business (e.g. on sales, on stock, on expenditure) Workbook: a workbook is a collection of more than one worksheet in the same spreadsheet. They can be used to divide data up into different categories and organise it, and different access rights can be set to each worksheet in the workbook if required. Rows: a row is a range of cells that goes across the spreadsheet (horizontal) Columns: a column is a range of cells that goes down the spreadsheet (vertical) They are used to organise data (e.g. with headings) within a tabular structure. Rows and columns can be hidden if necessary. Cells: a cell is an individual store uniquely identified by a column and row indicator. Each cell can be formatted independently of each other (e.g. colour, font, alignment) and can be protected to stop data being entered in them Ranges: a range of is a group of cells. Ranges are used when the cells contain similar data. e) Referencing is the use of cell identifiers to include the value contained within the cell in a formula or function. Relative referencing: this is when the cell referenced in a formula changes when the formula is copied to other cells. It ensures the correct cells are referenced when cells are copied to new rows. Absolute referencing: this is when a referenced cell in a spreadsheet formula needs to remain exactly the same when the formula is copied to other cells. f) A computer model comprises of a set of data about something and a set of rules that control what the data does. Using a spreadsheet to create and run simulations/models has advantages and disadvantages: Advantages Disadvantages - “What if...” questions can be asked without rebuilding a model from scratch each time a test is run - automatic recalculation: if a change is made then all related formulae and values change - graphs can be produced, automatically changing when values are changed - variables and constants can be used - model can be saved and backed up - model can be shared between different people in different locations - no additional software is required - might be quicker and cheaper to build a computer model than physical model - only one model needs to be built - it’s safer to run a simulation under extreme conditions than to use an actual model - computer-based models can be sped up or slowed down to see effects that are difficult to see in real life - model may not be an accurate representation of the real world - if model is based on people (value-judgements) then an accurate result may not be given - many variables may need to be considered and it’s easy to miss something out - producing an effective model may be time consuming 3.1.5 Relational Database Concepts a) Tables: a table is a data structure made up of rows and columns containing data about specific things. The table must have a unique name, as must the fields and records. Records: a record is a single row within a table. It is a collection of data about a single item or a single event. Fields: a field is an individual data item within a record. Each field should only contain a single data item. They can have their own data types and their own validation rules. Primary keys: a primary key is a field that allows each record to be uniquely identified - a simple primary key is one which is made up of a single field only - a compound primary key is one which combines more than one field to make a unique value Foreign keys: a foreign key is used to link tables together. It is a field in one table that is linked to a primary key in another table. Entities: an entity is a single object or thing you can store data about. Each entity becomes its own table (e.g. table about employees, table about customers, table about stock) and are linked to the other tables using relationships (e.g. customer related to item of stock bought) Attributes: an attribute is a characteristic of an entity (e.g. first name, last name for customer entity). Each attribute becomes its own field in a table. b) Relationships: these are links between fields in different tables. There are three types of relationships: One instance of entity Y –only one instance of entity X One instance of entity Y –many instances of entity X Many instances of entity Y –many instances of entity X c) Normalisation is a process applied to data structures to decrease redundancy and to increase its integrity. First normal form (1NF) - every data value is atomic (one piece of information per cell entry) - no repeating data (no record has repeating data) - primary key (each row must be uniquely identifiable) Second normal form (2NF) - must be in 1NF - non-key attributes are dependent on the entire primary key (no partial key dependencies) Third normal form (3NF) - must be in 2NF - no functional dependency between non-key items (no non-key dependencies) d) Advantages and disadvantages of normalisation include: Advantages Disadvantages - removes redundancy - increases consistency - increases integrity - easier maintenance - flexibility for future expansion - reduced database performance - problems with historical calculations e) A data dictionary is often called a database about a database. It contains metadata (data about data). Includes: table name, field name, data type, length, validation, relationships, security. f) Different data types must be used for different purposes: - Text/string – anything not requiring a calculation (would use for phone numbers) - Integer – whole numbers only, NOT telephone numbers - Real – numbers with decimal places - Boolean – one of two values (e.g. true/false) - Date/time - store age, dates, times g) The ability of databases to run queries is what makes them particularly useful. Parameter queries return fields from tables where the value of the parameter is matched. A simple query is one where there is only one parameter being searched. A complex query is one where there is more than one parameter. Complex query parameters can be joined in three ways: - AND – to include all records found in the queries - OR – to find records that match one or the other or both searches - NOT – an inverse query – searching for fields NOT within the parameter Parameters can be static or dynamic: - a static query is one whose parameters are hard coded into the query and cannot be changed by the end user - a dynamic query is one whose parameters are set by the end user at run time, usually by a dialogue box 3.1.6 Application Software Used for Presentation and Communication of Data a) Characters - any letter, number or symbol Paragraphs - used when a long document is being created - use of a carriage return at the end of the text - may have a style pre-defined to it - can format alignment, indentations, line spacing, font size/style and bullets/numbering Sections - a portion of a document in which page-formatting options can be set - until section breaks are formatted/inserted, the whole document is treated as a single section - allows layout of document to vary between different sections Frames - an area of a page that can contain text or graphics - can be positioned anywhere on page - DTP software uses frames; changes to one doesn’t after another - word processing software can use frames also, however doesn’t normally – changing one thing will affect another - DTP software has auto-flow feature – if text overruns in one frame, it continues over into another Headers/Footers - header is text/graphics which appears on a document in the top margin of every page - may include creator’s name, title and date - footer is text/graphics which appears on a document in the bottom margin of every page - may include page numbering, date and file name Footnote - used to briefly explain a word or phrase without including the explanation in the body of text - reference number placed next to word/phrase - explanation placed at foot of the page Pages - each printed side of paper containing the components of a document - may include text, graphics, tables, etc. b) Mail merge: 1) Create the data source (spreadsheet/database). 2) Create the template document (word processing/desktop publishing). 3) Insert merge fields from data source. 4) Check merge fields with data. 5) Complete the merge. Advantages of mail merge: - documents can be produced very quickly - only one copy needs to be proofread to ensure that all others are correct - the data source can be used for many different mal merge processes - the standard letter/template can be saved a reused c) Users can format attributes of a document including: - page size, settings and orientation - text position, size and style Page size, settings and orientation: - page size and paper to be printed on can be selected by the user - page margins can be set to keep content surrounded, or for placing a header/footer in - landscape or portrait can be set Text position, size and style: - appropriate text alignment can be set - font can be chosen - size of font can be appropriately set - text can be highlighted or styled with bold/italic/underline features d) Clip art images and collections of thumbnail images have advantages and disadvantages: Advantages Disadvantages - images are readily available - images are available immediately - use of clip art can reduce design costs - extra equipment such as cameras and scanners need not be purchased - choice of images is limited - quality of images ranges from very poor to good - not original or unique - may be subject to copyright e) Bitmap graphics are made up of pixels, each with a position on the image grid and a colour value. Vector graphics contain mathematical data that defines the key properties of every element in the graphic. Vector Bitmap - can be resized or rescaled with no loss of definition - size of vector graphic file is relatively small compared with a bitmap graphic for the same sized image - every component of graphic is described by its features - graphics can be grouped, keeping the same positioning - vector-based graphic files cannot be compressed - processing power required to display vector graphic is high - individual elements of the image can be edited - when resized, image quality is reduced - each pixel has to be saved individually, so the file size can be very large - components are only stored as pixels - more consistent with computing environment - bitmap graphics deal well with complex highly detailed images like photographs; each pixel can be addressed so subtle changes can be made - bitmap files can be compressed - editing bitmap file involves changing properties of pixels as a whole f) Graphics software for specialist applications provide libraries of graphical images and symbols that are often used in the application. They are developed with the involvement of manufacturers and professional bodies to ensure that all software relating to the production of maps uses the same symbols with the same meaning. The biggest problem with such graphics libraries is keeping them up to date (for example, in the continually-advancing IT industry. g) Text - text must meet the needs of the audience - rules must be considered at all times Images - use of images/graphics can help convey messages relating to the presentation - number of images per slide should be kept to minimum, and kept at suitable size - copyright must be considered Sound - sound effects can be set with animation effects (e.g. drum roll, chime, clapping) - can emphasise import pieces of information; however must be used sparingly as they can distract the audience - sounds can be in music or speech form also Video - video clips can be inserted into a presentation - can be set to play automatically or started by the presenter - don’t use too many video clips – they can distract the audience Animation - animation effects re visual effects that can be added to text or other objects, such as charts and graphics - it is possible to control the way each object appears on a slide - emphasises important points, controls flow of information, and adds interest to the presentation - order and timing of animations can be changed, along with the setting of animations to occur automatically Slide transition - transition effects can be applied to a slide to make the presentation more interesting - they govern how the presentation moves between each slide - speed of transitions can be set also Hyperlinks - a hyperlink is a coloured and underlined text or a graphic which, when clicked, takes the user to a file, a location in a file, or a page on the internet - they can move to specific slides in the presentation, different presentations, the internet, or another document Hotspots - a hotspot is an area on a screen which responds to a mouse click - this could be text or a graphic which takes users to another page Buttons - an on-screen button can be used to move from one slide to the next - a method of navigation involving buttons is interactive h) Computer and projector presentations Advantages Disadvantages - full range of features (e.g. special effects, hyperlinks, etc.) are abailable - doesn’t have to be followed in slide sequence - relatively easy to edit the presentation, and to see what’s on them - slides do not deteriorate with repeated use - temptation to overuse special features - requires computer and projector (both expensive and not very portable) - special software required to allow real time annotation of slides - no alternative in a power cut (unless paper copy is kept) Overhead projector presentations Advantages Disadvantages - easy to write on the slides to annotate them - overhead projector (OHP) is relatively cheap - presenter is able to read from acetate slides - special effects and interactivity cannot be used - can be difficult to jump to a slide out of sequence - changes require new slides to be printed - slides can deteriorate with repeated handling - blank acetate slides have to be bought and then printed on i) Manual transition involves some form of action from the presenter/viewer to move on to the next slide. It allows the presenter/viewer to run the presentation at their chosen speed, and to select from multiple different links somewhere else in the presentation. Automatic transition involves setting up a presentation to run automatically with no intervention required. Timings can be set up to change slides after pre-specified time periods. This is suitable for presentations where no presenter is required, however not suitable where the presenter may be trying to keep up with the pace of the slides. j) Three main structures for a presentation: - linear - non-linear - hierarchical A linear presentation is one where slides are shown in a pre-determined order – slides follow in a line from start to finish. A non-linear structure is one where slides can be accessed in any order. Each slide can be accessed by every other slide. This is usually accomplished with the use of action buttons. A hierarchical structure allows different, but pre-determined, slides to be jumped to from a slide depending on an option already selected. 3.1.7 The Role and Impact of ICT (ACTS only) b) Data Protection Act (1998) The Data Protection Act: - protects individuals from organisations (lot of information available about individuals collected by many different organisations) - limits the data held by individual organisations to only that which they need. The Data Protection Act has eight principles that must be followed: Personal data shall be processed fairly and lawfully Personal data shall be obtained only for one or more specified and lawful purposes, and shall not be further processed in any manner incompatible with those purposes Personal data shall be adequate, relevant and not excessive in relation to the purposes for which they are processed Personal data shall be accurate and, where necessary, kept up to date Personal data processed for any purposes shall not be kept for longer than is necessary for those purposes Personal data shall be processed in accordance with the rights of data subjects under this Act Appropriate technical and organisational measures shall be taken against unauthorised or unlawful processing of personal data and against accidental loss or destruction of, or damage to, personal data Personal data shall not be transferred to a country or territory outside the European Economic Area, unless that country or territory ensures an adequate level of protection for the rights and freedoms of data subjects in relation to the processing of personal data Individuals have certain rights: - right to subject access - right to prevent processing likely to cause damage or distress - right to prevent processing for the purpose of direct marketing - rights in relation to automated decision making - right to compensation if damage and distress is suffered by the Act being contravened Glossary: Personal data – any data relating to an individual Data – anything that is held on an individual as part of a record Processing – obtaining, recording or holding the information or data Data subject – the individual data is being held about Data controller – worker in a company who makes provisions to comply with the DPA Data processor – any person who processes the data on behalf of the data controller Recipient – individual given the data in order to process it some how Third Party – individual who receives the data for processing Information commissioner – individual who’s responsible for ensuring the DPA is being adhered to, by giving advice, running training sessions and investigating complaints Computer Misuse Act (1990) The Computer Misuse Act: - was introduced to protect data held by companies from hackers The Computer Misuse Act has four main provisions: Unauthorised access to computer material Unauthorised access with intent to commit or facilitate the commission of further offences Unauthorised acts with intent to impair, or with recklessness as to impairing, operation of a computer Making, supplying or obtaining articles for use in computer misuse offences Benefits of Computer Misuse Act Problems with Computer Misuse Act - Without it, theft of electricity was the only crime a hacker could be charged with. - Intent must be proved (accidental intrusion isn’t punishable) - Can be difficult to find who is responsible - Confidential information can be obtained and accessed, and then gotten rid of before they are caught Copyright, Designs and Patents Act (1988) The Copyright, Designs and Patents Act: - makes it illegal to steal or create unauthorised copies of software - also covers manuals, books, CDs and music Benefits of Copyright, Designs and Patents Act Problems with Copyright, Designs and Patents Act - people who put in the time and effort to produce books, music and software deserve to be rewarded in royalties - allows individuals and corporations who invest time and money to reap their rewards - when buying software, you’re usually only purchasing a license to use the software – these licenses can be difficult to understand, and many people think because they can’t be seen, then it isn’t a crime to copy/distribute this software - copying CDs/downloading copyright music damages people’s livelihoods and hinders future developments The Regulation of Investigatory Powers Act (2000) The Regulation of Investigatory Powers Act: - introduced to address concerns about the use and misuse of communication interception techniques by public and private organisations - makes it a criminal offence to monitor communications without lawful authority - ‘the interception has to be by or with the consent of a person carrying on a business, for purposes relevant to that person’s business, and using that business’ own telecommunications system’ Benefits of Regulation of Investigatory Powers Act Problems with Regulation of Investigatory Powers Act - Companies can monitor what its employees re doing - Ensures facilities are being uses for legitimate work - Helps keep company secrets unrevealed - Any form of monitoring can be seen as a breach of trust - Many people like to ‘cling on’ to their privacy - Concerns about what controls there are on organisations who monitor communications The Electronic Communications Act (2000) The Electronic Communications Act: - government wanted ‘to make the UK the best place in the world for e-commerce’ and to ‘create a legal framework so that people can be sure about the origin and integrity of communications’ The Electronic Communications Act has two make parts: Cryptography service providers – this allows the government to set up a register of approved cryptography suppliers Facilitation of electronic commerce, data storage – this recognises digital signatures, which are now admissible in law Benefits of Electronic Communications Act Problems with Electronic Communications Act - contracts signed over the Internet have the same legality as those signed by hand (increasing security of e-commerce and ensures legal backing for contracts) - lots of legislation against digital signatures, so there’s now legislation to remove laws preventing digital signatures, but this takes time - always a security risk The Freedom of Information Act (2000) The Freedom of Information Act: - deals with access to information on any topic from any public authority (including government, the health service, schools and police) - allows anyone to make a request, giving their name, address and a description of what they want Benefits of Freedom of Information Act Problems with Freedom of Information Act - information that wasn’t accessible to the general public is now available - increased accountability (public authority cannot hide decisions they make) - any information can be requested, however it may be withheld to protect various interests/may come under an exception - public authority doesn’t have to confirm or deny the existence of the information that you have requested - doesn’t have to provide information if an exemption applies, if the request is too vague, if it’s similar to a previous request, or if the cost of collating and producing the information exceeds an appropriate limit
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