Information Technology 9626/12 February/March 2021: question paper and mark scheme

Mark scheme

1(a) 1 There are two types of hardware: application hardware and system hardware. Hardware consists of the programs used to direct the operation of a computer. Hardware is the collection of physical components that constitute a Π computer system. A device driver is an example of an item of hardware. 1(b) 1 A hard disk drive allows quicker access to data than RAM. RAM is portable and very easy to move from device to device. RAM stores active program data. Π Per unit of memory, RAM is far cheaper to buy than a hard disk drive. 1(c)(i) Four from: 4 Max two from: Comprises memory, control unit and arithmetic logic unit (must have at least two) Tends to be contained on an integrated circuit chip called a microprocessor Max three from: Control unit retrieves/fetches instructions from the computer’s main memory… …interprets/decodes instructions… …carries out/executes instructions All input data are transferred via CPU’s memory/registers Memory/registers store instructions as well as data Data is stored in the CPU memory whilst a calculation or instruction is being carried out. Input data are transferred to the arithmetic and logic unit for processing ALU: Arithmetic unit makes use of the four basic arithmetic functions (i.e., addition, subtraction, multiplication, and division) ALU: Logic unit uses certain logic operations such as comparisons, selections and matching 1(c)(ii) Motherboard – two from: 4 The main printed circuit board of a computer Connects the main components of a computer Contains mass storage interfaces Contains serial and parallel ports Contains USB ports Contains network port Contains expansion slots Contains controllers required to control standard peripheral devices Contains the connectors for attaching additional boards Contains the BIOS chip/chipset Contains means of plugging in/socket for CPU Contains RAM slots Sound card – two from: An expansion board that enables a computer to manipulate and output audio Enables the computer to output sound through speakers connected to the board Enables the computer to receive sound input from a microphone Enables the computer to manipulate sound stored on a disk Nearly all sound cards support MIDI, a standard for representing music electronically

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2(a) 1 It is easier for users with physical disabilities to use a keyboard or mouse than make gestures. It is easier to enter text with a gesture-based interface than with a command line interface. Gestures are more accurately interpreted than mouse clicks. Some gestures may be unintentional but still initiate a reaction from Π the device. 2(b) 1 Dialogue interfaces are more difficult to use than command line interfaces. A dialogue interface uses less memory than a command line interface. A dialogue interface may not operate reliably if there is background Π noise. Dialogue interfaces have unlimited vocabularies. 2(c) Eight from: 8 Advantages With a CLI the processing speed tends to be faster than GUI A CLI uses less memory/resource… …as it doesn’t need to store WIMP features CLI doesn’t require graphics software or a high-resolution monitor CLI is less likely to change over time whereas GUIs tend to change regularly, meaning less need to learn how to use a new system CLI users only need to utilise a keyboard to navigate the interface, often resulting in faster performance Taking a hand off the keyboard to move the mouse is slower than using a CLI for many users Disadvantages CLI requires the user to have to learn many commands unlike GUI CLI commands can be slower to input particularly for inexperienced users… …long lines of text need to be entered rather than a few clicks of a mouse CLI commands are more difficult to edit With a CLI it is more difficult to view different items on one screen when multitasking A CLI is often very basic and can be more of a strain on a user's vision More likely to make mistakes typing commands At least two of each required to obtain full marks Must be a proper evaluation to obtain full marks Max. six marks if bullets/list of points Must have expansions or direct comparisons to be a proper evaluation

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3(a) CD ROM, hard copy text book, printed magazine (any two) 1 3(b) Two from: 2 It contains data that doesn’t change You cannot add data to a printed newspaper There is a fixed amount of information in a printed newspaper Printed newspaper tends to go out of date quickly

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4(a)(i) Two from: 2 No validation check would pick up that the 11 has become 12 12/11/1992 would pass a format check as it is still dd/mm/yyyy 12/11/1992 would pass individual range checks as 12 is still less than or equal to 12/less than 13 and more than 0 4(a)(ii) Visual check to compare the data in the database to the original source 1 4(b) Two from: 2 Length check on Membership number to make sure it is 5 characters in length Range check on Membership fee to make sure it is between 10 and 50

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5 Seven from: 7 Advantages Once the program is already compiled into machine language, there is no translation software that the user has to keep up to date Compiled software can run faster than interpreted software Compiling a program is a much quicker process than interpreting Compilers also improve security for programmers… …by making it much harder to copy Joan's code Disadvantages Can only be used on one operating system… …Joan's target audience will have different computers and operating systems… … Will need to use an interpreter if she wishes to share the software It is slow/more difficult to debug the program… …the whole program needs to be compiled again after an error is corrected It uses up more memory than an interpreter… …as the whole program has to be loaded Once compiled, any changes to the original high-level code will require the program to be compiled again At least one of each required to obtain full marks Must be a proper evaluation to obtain full marks Max. five marks if bullets/list of points Must have expansions or direct comparisons to be a proper evaluation

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6 Eight from: 8 Access to fast broadband can be better for those people living in urban areas than for those living in rural areas/poor for than those living in rural areas Without access to fast broadband people in rural areas are less likely to be up to date with the latest internet technologies Buying televisions/personal computers/smartphones can be more expensive in rural areas People with a higher level of education may find mobile phones/computers easier to use than those with a lower level of education Richer people are more/poorer people less able to afford the latest versions of televisions/personal computers/smartphones computers Older people can find mobile phones/computers harder to use than younger people Young people have grown up with the technology/older people may feel they are too old/unwilling to learn about new technology The quality of connection to the Internet may be poorer in underdeveloped countries The price of connection to the internet may be prohibitive in underdeveloped countries People may have access to televisions/personal computers/smartphones computers but choose not to use them for reasons of e-safety/privacy There may be a lack of broadband infrastructure/5G in rural areas/underdeveloped countries Underdeveloped countries may have lower-performance computers Disabilities of some users may inhibit the use of smartphones/computers

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7 Four from: 4 The internet is an international network of networks of computers/the physical connection between networks of computers The World Wide Web is the general term for accessing information over the internet/information accessed using the internet The World Wide Web is a system of internet servers that support specially formatted documents The World Wide Web is an information-sharing model that is built on top of the internet The World Wide Web uses the HTTP(S) protocol, which is only one of the many protocols used in the internet to transmit data

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8 Five from: 5 Provides past, present and prediction information Helps in decision making Management information systems are used to create reports on aspects such as sales, revenue and production Management information systems reports can include charts on aspects such as sales, revenue and production These reports are provided at regular intervals to managers at all levels to help them evaluate their companies' performance Can compare daily/weekly/monthly reports to previous reports Managers are able to spot trends, such as revenue growth or reduction

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9 Six from: 6 A mobile phone network allows mobile phones to connect/transmit data through cell towers/base stations… …and is divided into thousands of overlapping geographic areas/cells A typical cellular network can be thought of as a mesh of hexagonal cells Each cell has its own base station at the centre The base stations provide the cell with the network coverage which can be used for transmission of voice, data and other types of content The cells slightly overlap at the edges to ensure that users always remain within range of a base station RF signals are transmitted by an individual phone to a base station RF signals are then re-transmitted from the base station to another base station/mobile phone Transmitting and receiving are done over different frequencies Base stations are connected to one another via central switching centres The central switching centres track calls and transfer them from one base station to another as callers move between cells A mobile phone is a two-way radio containing both a low-power transmitter and a receiver A cell typically uses a different set of frequencies from neighbouring cells

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10 Six from: 6 An information processing system which has to respond to inputs instantaneously… …quickly enough so as to be able to control an output properly Real-time processing systems have to be programmed very carefully to ensure that no input events are missed Controlling a car park barrier has to deal with input events continuously A car park barrier system will be providing input data to the computer using light sensors/inductive loops/pressure sensor Is not effective with very large volumes of data… …but control systems/car park barrier systems usually have small amount of data to deal with so not a problem Car park barrier system must react to the approach of a car immediately… …other types of processing might cause drivers to be frustrated/queues to form Requires complex and expensive operating system Real-time systems are not easy to develop Must be a proper analysis to obtain full marks Max. five marks if bullets/list of points Must have expansions to be a proper analysis

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11 Four from: 4 There is a field in the database called Examdate which contains the date of an exam The query is being used within a calculated field If the date in Examdate is after today’s date, ‘not yet’ would be displayed If the date in Examdate is equal to today’s date, ‘today’s the day’ would be displayed If the date in Examdate is before today’s date /otherwise, ‘you’ve missed it’ would be displayed

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12(a)(i) Two from: 2 A cell is a specific location within a spreadsheet and is defined by the intersection of a row and column Cells are often referenced by a letter and number combination For example, J11 is the cell containing the value 32 Must have an example to gain both marks 12(a)(ii) Two from: 2 Rows run horizontally in a worksheet Each row is identified by a number in the row heading Row 13 is highlighted in the spreadsheet and contains the values 24, 51, 18, 12 and 26 Must have an example to gain both marks 12(a)(iii) Two from: 2 Columns run vertically in a spreadsheet Each column is identified by a letter in the column heading Column J is highlighted in the spreadsheet and contains the values 32, 45, 18, 29 and 42 Must have an example to gain both marks 12(a)(iv) Two from: 2 A worksheet or sheet is a single page in a spreadsheet Each worksheet has a name and by default the worksheets are named Sheet1 etc. In this example, they are named Data/Outgoings/Income Must have an example to gain both marks 12(b) Six from: 6 Household bill calculations can be performed more quickly/more easily/recalculated automatically ‘What if…?’ questions can be asked without redoing all the calculation each time prices change Models provide quick answers to events that may take months to actually happen Graphs that are produced to show finances over time will automatically change (as new values are added/old values altered) Graphs of outgoings/income can be produced automatically/more quickly/no manual method is required Quantities can be entered more accurately because of computer-based validation Conditional formatting allows you to highlight certain values that match specific criteria... ... such as seeing at a glance whether outgoings are greater/less than income Absolute and relative cell referencing make sure you only increment the parts of a formula you need to... ...and allow you to change prices/costs of individual items to see the effect

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13 Eight from: 8 Indexed sequential access is a mixture of sequential access and direct/random access With sequential access, records can be accessed sequentially in the order they were entered With sequential access, records are read one by one until a match is found Indexed sequential A set of hash tables known as indexes contain "pointers" into the records/index value is generated The index is a pointer to whereabouts on the disk the record is stored Individual records can be retrieved without having to search the entire file Data is organised into records which consist of fixed length fields Records can be found randomly using an index Indexes can be searched quickly, thereby allowing the database to access only the records it needs Searches use an index which will narrow down the records/data to be searched Then that section of the file is searched sequentially to find the record required Example An index table would contain all the letters of the alphabet in sequence and the corresponding part of the disk where names beginning with those letters can be found For names beginning with P the part of the file containing all the As to Os can be ignored/ the disk is accessed where the Ps begin All the records beginning with P still have to be read one by one until Patel is found