As Computing Mark Scheme

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS GCE Advanced Subsidiary take and GCE Advanced train MARK SCHEME for the May/June 2009 research paper for the guidance of t for each oneers 9691 calculation 9691/01 Paper 1 (Written Paper 1), maximum raw mark 90 This mark scheme is published as an aid to teachers and netdidates, to indicate the requirements of the examination. It shows the soil on which Examiners were instructed to award marks.It does non indicate the details of the discussions that took place at an Examiners meeting before marking began, which would have considered the acceptability of alternative answers. jester schemes must be read in conjunction with the question papers and the report on the examination. CIE will not enter into discussions or agreement in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2009 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllab subprograms and some Ordinary Level syllabuses.Page 2 1 (a) scoring Scheme Teachers version GCE A/AS take aim May/June 2009 computer program 9691 Paper 01 (i) To al modest the drug drug user to guide the computer data/ stir data into computer understandable jump (ii) To allow the computer to give information/communicate with the computer/to change information from computer into clement understandable form (iii) To keep data while the computer is not using it (1 per dotty) 3 (b) -Black and white laser -e. g. white plague in office to discover letters -Produces high quality/speedy so does not cave in large queue on a LAN -Colour laser -e. g. To start reports for a meeting -High quality step upputs/ whoremonger produce large step quickly -Dot Matrix e. g. Print receipts at checkout/tickets on rail charge -Produces more than one copy at a time, one for customer + one for shop -Inkjet -e. g. Doing homework at home -Relatively nickel-and-dime(prenominal) and slowness does not matter -Plotter -e. g.Produce architects plans -Precision order of payment tool -Braille printer -Producing documents/books for blind people -Outputs physical/3D form of data (3 per type, max 3 types, max 9) 2 (a) (i) Name school text/String/ of import/alphanumeric Description Text/String/alpha/alphanumeric Cost Currency/integer/real/float Whether Boolean Number Integer (1 for first three, 1 for last 2) (ii) Field Sizes 10 50 4 1 1 66 50 250 8 4 313 bytes (1) 9 2 Total (1) for showing that the field sizes should be added up multiply Total by 1000 (1) = 66000 to 313000 bytes Add extra (10%) for overheads (1) = 72600 to 344300 bytes Convert to levelheaded unit (? 024) (1) = 70. 9Kb to 344. 3Kb. (5 possible mark points, max 4) 4 UCLES 2009 Page 3 score Scheme Teachers version GCE A/AS LEVEL May/June 2009 computer programme 9691 Paper 01 (b) Advantage -Processed/Searched more easily/quickly/Estimate of deposit size is easier -e. g. When a customer wants to know the availability of an ite m the unload can be found quickly/ slangs selection of storage easier evil -The size of fields must be determined before use so space is often wasted/not sufficient -e. g. The commentary field may not be large enough for a particular item. 1 per -, max 4) 4 3 -Working from home -Fewer journeys/more waive time/less supervision -Different types of jobs/jobs lost/job opportunities arising -Production line/manual of arms jobs being lost/replaced by more technical jobs -Work done can be more visible to managers -All work/times working can be seen/ soupconing to rewards where appropriate/sanctions when poor effort -Safety of workers is improved -Computers/robots do self-destructive tasks/can be used to accu prescribely monitor dangerous processes -Work time can be less rigid -Work can be fitted in round other(a) commitments/leads to simpler ways of job sharing -The 24 hour job/office/commitment/world workforce -Workers may always be contactable/ byout the world/communications. (Up to 2 per group, max 3 groups, max 6) 6 (a) Line X A OUTPUT CONDITION 1 1 3 1 1 4 1 1 1,1 5 2 1 6 2 1 line up 3 2 4 4 2 4 2,4 5 3 4 6 3 4 FALSE 7 3 4 (1 for values of X and matching line be 1 for values of A corresponding to values of X 1 for giving correct outputs 1 for giving 2 conditions) 4 (b) (i) Change X = 3 to X = 11 (ii) -A first line to allow user to enter value (N) -UNTIL X = (N + 1) 1 2 4 UCLES 2009 Page 4 (c) e. g. purpose Scheme Teachers version GCE A/AS LEVEL May/June 2009 class 9691 Paper 01X=5 REPEAT A=X*X OUTPUT X, A X=X+5 UNTIL X = 25 END Mark points -Begins with 5 (as first output) -Loop with working condition -Counter the right way incremented 5 (a) (i) -Options appear on screen from which to select -Selection may lead to submenus -Menus arranged in a tree structure (from single foundation to many branches) Use In a passive information carcass e. g. Tourist guide at a train station. (1 for use, + 2 other -, max 3) 3 3 (ii) -Follows a spoken language allo wing user to input queries in normal vocabulary/syntax -Computer understands keywords/positions in sendence to get mood of syntax -Will then search database for keyword to provide output or responses. Use e. g. On an expert system or search engine. 1 for use, + 2 other -, max 3) 3 (b) -Provides utility programs to allow user to carry out maintenance tasks (any 3) -Provides security measures like passwords and identifications. -Controls the hardwargon and the operations they allow. -Provides translators to convert bundle into a form useable by the computer. -Manages interrupts. -To provide a weapons platform for the execution of software (1 per -, max 3) 6 (a) (i) Data is transmitted on a single wire/one sec at a time. (ii) Data is transmitted along a crook of wires/one byte (or more) at a time. (iii) Data can only be transmitted in a single direction. (iv) Data can be transmitted in both directions but only one at a time. (b) (i) -Each byte rents an dismantle number of 1s - A special bit is set to 0 or 1 to check that total is even. Byte is checked for even number of 1s after transmission. (1 per -, max 2) (ii) -When two bits are in error the errors cancel each other out/10101001. 3 1 1 1 1 2 1 UCLES 2009 Page 5 7 Mark Scheme Teachers version GCE A/AS LEVEL May/June 2009 Syllabus 9691 Paper 01 -Data collected on site/by drilling /observation/explosions -Data collected remotely/by satellite/by electronic means -Collected data input to system via HCI/automatically -Data input is compared to library of data to find matches -by inference engine -Using rules found in rule base -Decisions made about geologic structure report through HCI. (1 per -, max 4) 4 8 a) -Site map -a diagram showing the way the disparate screens fit together -shows the links between screens, -Gantt chart/ encourage chart -shows the different split that need to be developed -shows which split of the development are independent and which are reliant on each other. -Spider diagram -to show interaction between the different elements of the solution -and those split which are independent of each other. -Flow diagram -to show the order of producing the parts of the solution -or to show the flow through the proposed site. (Up to 2 groups, up to 2 per group, max 4) 4 (b) -Documentation for proprietor of site -will be paper based -will contain instructions for changing/maintaining site -Documentation for viewer/visitor to site -will be on-screen -giving detailed help on searches/use of facilities/communication with site owner 4 9 -Sound -Music to accompany the pictures/speech to explain the pictures. Video/animation -Moving pictures to split up describe the object on the site -Automatic hard copy/ parsimoniousness -Automatic downloading of data to printer/hard drive for future reference. -Hyperlinks -Allowing access to different sites/parts of site (Up to 2 groups, up to 2 per group, max 4) 4 10 Colour -Contrast -Corporate schemes -Aggressive/passive/soothing bu rnish schemes -Consistency over site to make site look cohesive -Use colour to provide emphasis -Accessability issues e. g. colour blindness UCLES 2009 Page 6 Mark Scheme Teachers version GCE A/AS LEVEL May/June 2009 Syllabus 9691 Paper 01 Layout -Consistent layout so user gets used to what is where. Important things to top and left -Data spread out crosswise whole screen -Tab order -Group similar data together essence -Limit to amount of content on a page -Content on a page is cohesive -Content matches the published intentions of the site -Content is of sensible type and narration age for audience. (1 per -, max 2 per group, max 6) 6 11 -The bit rate is a measure of the rate that data can be sent across the communication medium -Different communication media have different bit rates -For simple text/still picturesa low bit rate connection is adequate -because volume of data per page is low and fixed -For (live) video/soundbit rate needs to be high -because large volume of data which must be downloaded in real time because -information is time sensitive. 1 per -, max 4) 4 12 (a) (i) -Custom write software is especially written/according to the requirements of the customer -Off the shelf is quickly available/needs tailoring to the needs of the customer 2 (ii) -no delay as it is ready immediately -No shortage of experienced users/ready trained/No learning curve -Software should be error free -Help available through Internet/colleagues/courses -Compatible with other users/software (1 per -, max 2) (b) (i) -Check data input to ensure it matches source data -Typed in twice -by different people/at different times -inputs checked against each other for errors -manual check by comparing -screen output of input with original document. (1 for first -, + any 2 other -, max 3) (ii) -Check data input is sensible/follows set rules/are reasonable -Data type/should be numeric -Data format/should be in currency form/xxx. xx -Length check/input should be x characters -Pr esence check/something has been input. -Range check/value between 0 and some focal ratio limit (1 for first -, + any 2 other -, max 3) 2 3 3 UCLES 2009