Autumn term Year 11
Scheme of Work
GCSE (9-1) Computer Science
Pearson Edexcel Level 1/Level 2 GCSE (9-1) in Computer Science (1CP1)
Autumn term Year 11 Scheme of Work
Autumn term Year 11
Assumptions
This scheme of work is based on the assumption that the students have followed the Free Support Materials Schemes of Work for Year 10. If not, it is important to check the content of each lesson to confirm that it has or has not been previously covered. However even if it has already been covered teachers may find some of the suggestions and activities I the associated booklet useful to reinforce knowledge or use as revision.
The lessons in the various schemes of work total 150 hours altogether (see course planner); the guided learning hours for GCSE Computer Science are 120. It is expected that centres will modify the schemes of work and the course planner as required to fit their own timetabling.
The programming language used here is Python 3.0. Centres can of course use any of the other languages in the specification, namely Java and C-derived (C, C++, C#) and use equivalent examples from these languages.
All the Year 11 resources now account for the revised submission date of 31 March as required by Ofqual.
Explanations
The course has been broken down into six terms. Over the course, lessons are split into the six topics in the subject content and the colours in the schemes of work mirror the colours of the topics in the course planner.
Weeks are numbered from one in each term and there are two lessons each week. This scheme of work details the content to be covered in the Autumn term of Year 11. Where applicable, problem solving and programming are taught together to increase computational thinking skills, which will also be used in the other subject content topics.
The references to the specification represent the specification content that is covered in the lesson. During the problem solving and programming topics, many lessons cover a range of content but only the main specification reference is given. You are strongly advised to use the specification alongside this scheme of work.
The lesson summary gives an overview of the lesson content. The title in bold refers to the subject content headings given for each topic in the specification.
The lesson content gives suggestions on how this material could be taught. Example activities for each lesson are given in the activities files. The activities are numbered with the lesson number, for example Activity 1.2.3 is the third activity for Lesson 2 in Week 1. These activities are provided to give teachers ideas of activities and programming.
Autumn term Year 11
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 3.3.1 / Problem solving and programming / Welcome students back. Explain the course for this year, go through overall course planner if you have used it.
Problem solving activity: Go to ask the students to complete the activity. You might want to copy out the activity rather than direct students to the website so that they do not go directly to the solution!
Start problem solving and programming activity for this and next lesson which is Task 1 from the 2015 Controlled Assessment. This is a secure download from
If you do not have access to this speak to your examination office for advice.
This task should take about 1 ½ hours to complete.
Homework: Issue Sample Assessment Material for NEA. Go through very briefly. Ask students to read through it and note down questions/comments to discuss next lesson. / cs4fn, Queen Mary, University of London (
2015 Controlled Assessment Task 1 (legacy specification 2013)
SAM NEA
2 / 3.3.1 / Problem solving and programming / Ask students if they have any questions on the Sample Assessment Material issued for homework.
Students should then complete Task 1 2015 Controlled Assessment.
Extension: Ask students to validate the data and write the data to a file (this is NOT a requirements in the original task).
Homework: Ask students to complete the extension to Task 1. / 2015 Controlled Assessment Task 1 (legacy specification 2013)
SAM NEA
Week 2
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 3.3.1
3.3.2
3.3.3 / Compression / Starter: card sort activity in Activity 2.1.1 to elicit prior knowledge/recall of data size units.
Share what students will be learning i.e. how and why computers compress and encrypt data.
Remind students that bitmaps, audio and video files can be very large. Explain that compressing data reduces its file size. Ask students to suggest reasons why reducing file size is desirable (to save on storage space and speed up file transfer).
Give students an opportunity in Activity 2.1.2to discover how compression affects file size.
Use the ‘Honey I shrunk the data!’animation andgame to introduce three different strategies for shrinking data – ‘keep them all and make them small’ (lossless), ‘squeeze them more and open the door’ (lossy) and ‘save the best and scrap the rest’ (superchannel): Discuss with the class the pros and cons of each strategy. Make sure that students understand the key difference between lossless and lossy compression techniques, i.e. that the former retains all the original data while the latter permanently discards some of it.
Show the YouTube video ‘Run Length Encoding Visualization’to introduce the concept of Run Length Encoding (RLE):
Give students the opportunity to experience RLE compression in action by decompressing a 4-bit colour image encoded using RLE (Activity 2.1.3). Read the binary numbers aloud to students or give them the binary codes to read for themselves
(seeendnote [i]).
Homework: Ask students to complete Activity 2.1.4. / Week 2
Lesson 1 activities
Files in Autumn term Year 11 Resources
‘Honey I shrunk the data!’ animation and game
‘Run Length Encoding Visualisation’ YouTube video
2 / Stage 1: Analysis / NEA Preparation: Requirements / Introduce the NEA Prep lessons (use lesson summaries).
Go thought the differences between the preparation session and the ‘real thing’. Discuss the restrictions there will be when completing the real NEA (page 15 Security, and page 35 in the specification).
Explain that there will be less class time when doing the NEA prep so they will be asked to do some work at home. Reinforce that they will not be able to do this in the real NEA.
Explain that their work has to be presented in a written report but that there is not much writing! Only what has to be assessed. Note that all that has to be included is in the SAM itself with more details on page 19 of the specification.
Go through the questions that the students have noted as homework.
Explain the first task – they must create a list of requirements which are what the user wants from the final programmed solution. Refer to specification and SAM.
Split the students into small groups and get them to jointly create a draft list.
Homework: Ask students to take the draft requirements from their group and finalise with any more they can think of. The work should be presented as a well formatted, detailed list. / SAM NEA
Specification
NEA Delivery Guide (use for reference throughout the NEA preparation)
Week 3
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 3.3.2
3.3.3
3.3.4 / Compression:lossless run-length encoding / Start the lesson by recapping why files are compressed, i.e. to make them more space-efficient and to enable them to be transferred quickly. If you feel students need more practice encoding or decompressing 4-bit colour images using RLE, you could select one student to read out their data (Lesson 1 homework activity) and ask the rest of the class to decode and draw the image. Alternatively, you could put students into pairs and have them decode each other’s images. Some groups may need to recap the data size units i.e. bits, bytes, MB.
Use the 4-bit colour image in homeworkActivity 2.1.4to walk students through how to calculate the size (in bytes) of the uncompressed and the compressed files, pointing out the small size reduction.
Size of compressed file in bytes
= number of codes x number of bits in each code / 8
= 84 x 6 / 8 = 63 bytes
Size of uncompressed file in bytes
= number of squares in grid x 2 / 8
= 256 x 2 / 8 = 64 bytes
Explain to students the need to multiply the number of squares in the grid by 2 as each square in the grid is one of four colours, which is represented by a 2-bit number.
Now give students the opportunity to do these calculations for themselves on the image they encoded in their Lesson 1 homework activity in Activity 3.1.1.
Point out that the advantage of a smaller file is gained at the expense of the computer having to carry out more processing – the file has first to be compressed and then it has to be decompressed before it can be used. This is especially true in this case, where compression only saves 1 byte. Ask students to consider whether the file would compress more or less if colours were represented by 4-bit codes.
Introduce students to the RLE calculator: Give them an opportunity to try it out and get to grips with how it works inActivity 3.1.2.
Show students the outline design for an RLE algorithm written in structured English. Ask them to complete the algorithm and check that it works. (Activity 3.1.3)
Homework:Challenge students to write a program to implement the RLE algorithm in Activity 3.1.4.
Extension:Ask students to write a program to decompress text encoded using RLE in Activity 3.1.5. / Week 3
Lesson 1 activities
Autumn term Year 11 Programming Solutions
2 / Stage 1: Analysis
Stage 2:
Design
2.1 Solution Design / NEA Preparation: decomposition
NEA Preparation: designing the algorithm(s) / Make the point that requirements for a solution are the users’ point of view but that these requirements are going to be turned into a programmed solution.
This requires taking the requirements and decomposing them into sub-problems which can be used in the design and potentially programmed later. There might not be a 1 to 1 match between requirements and sub-problems.
They should submit:
- A short description of what each of the sub-problems will do
- A short explanation of the reasoning behind the decomposition submitted (reinforcing computational thinking)
Ask them to note down any problems they have in starting the decomposition. / SAM NEA
Specification
Pseudo-code booklet
Week 4
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 3.3.2 / Compression:losslessmethods of compressing data / Start the lesson by recapping what students have learnt so far about RLE compression. Reiterate that RLE works best on files that contain long runs of repeating data. It is not much use for files where this is not the case and, in some instances, can make the file size bigger rather than smaller. (Students should have realised this for themselves after completing Activities 2.1.3and 2.1.4in the last lesson.)
Use the nursery rhyme ‘The wheels on the bus’ to introduce a different approach to compressing files with repeating patterns of data: the LZ algorithm(Activity 4.1.1).
Demonstrate that a considerable size reduction can be achieved by using a lookup table and that the original file can still be reconstructed without any loss of quality (Activities 4.1.2 and 4.1.3).
Using the Computer Science Unplugged worksheet ‘Short and Sweet’ (page 31 of demonstrate how even better compression can be achieved if, instead of words, repeating patterns of letters are stored in a lookup table.
Homework: Ask students to complete Activity 4.1.4. / Week 4
Lesson 1 activities
Computer Science Unplugged (
2 / Stage 2: Design
2.1 Solution design / NEA Preparation: designing the algorithm(s) / Review any major problems that the students might have had when starting the algorithm(s).
Go through the bullet points on page 21 so that they are clear what their algorithm(s) should include.
Go through the mark scheme and reinforce that they need to keep referring to their requirements. Let them add to them if they need to.
During this lesson go round the class and check individual work – and reinforce that the real NEA must be their own work.
Homework: Students should complete their algorithms and cross-check with their requirements and decomposition from Analysis. / SAM
Specification
Pseudo-code booklet
Week 5
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 3.3.2 / Compression:lossy methods of compressing data / Start the lesson by reminding students of the ‘squeeze them more and open the door’ approach to compression introduced in the ‘Honey I shrunk the data!’ game.
Show students the bitmap image. Point out that, although large parts of a photograph may look the same, each individual pixel is likely to be slightly different from the pixels on either side of it. This is why a lossless compression algorithm can’t do much with this type of data.
Explain that lossy compression algorithms exploit characteristics of human beings: there are some sounds the human ear can’t hear and some subtle differences in colour the human eye can’t detect, and our brains can ‘fill in the gaps’ if they notice something is missing.
Use the bitmap image to explain in simple terms how the JPEG compression algorithm works. (The picture is divided into blocks of 8x8 pixels; the data within the 8x8 pixel block is analysed and ranked for its importance to visual perception; key data is retained and less important data is discarded.) This is achieved by replacing the colour values of some pixels.
Ask the students to complete Activity 5.1.1which gives them the opportunity to experiment with JPEG image compression, using an online photo editor.
Explain that the MP3 compression algorithm works by removing sounds that cannot be detected by the human ear. Supply students with a WAV file of your choice and give students the opportunity to experiment with different compression algorithms for music(Activity 5.1.2).
Homework: Ask students to complete Activity 5.1.3 to create a summary sheet for themselves by answering the questions on lossless and lossy compression. / Week 5
Lesson 1 activities
Online photo editor, e.g. pixlr
Image in Autumn term Year 11 Resources
2 / Stage 2: Design
2.2 Test strategy and initial test plan / NEA Preparation: what is a test strategy?
Creating the initial test plan / Check progress with the solution design.
Explain what a test strategy is (their overall plan on how to test). They should write a short paragraph including their method (top-down, bottom-up, both), the data they will be using (normal, boundary and erroneous) and their reasons for following this strategy. High marks for this section should consider their own requirements for testing rather than general terms, and be followed through in the test plan itself (page 23).
Explain to the students that they will now create an Initial Test Plan which will test against their requirements. This will then be ‘banked’ but when they start their implementation they will be expected to add to it, e.g. refinements, error corrections etc. as would happen in a real life development.
Homework: Complete any unfinished work on the test strategy or Initial Test Plan then critically review it to check that it is complete. / SAM
Specification
Initial test plan template
Week 6
Lesson / Spec ref / Lesson summary / Lesson content / Lesson resources
1 / 4.2.4 / Data storage: magnetic / Recap how some computers need to store data and instructions permanently in secondary storage and review the units used for data storage.
Explain that there are three main ways in which data is stored permanently on devices. Pass round examples (or show images) of the three main types of secondary storage and ask students to identify them:
1.Magnetic storage, e.g. a hard disk drive:
2.Optical storage, e.g. a CD or DVD drive:
3.Solid state, e.g. a solid state drive:
Tell students that each storage device has a maximum storage capacity which is measured in bytes.
Ask students to continue to research the type of storage devices that are available (Activity 6.1.1)
How is data stored magnetically?
Show this Royal Institution ‘Ghost in the machine’ video to give students an idea of how data is stored magnetically: minutes). Hard disks contain metal platters coated in iron oxide and data is stored by magnetising the surface of the disk. The platters rotate and the read/write heads float above the surface detecting and modifying the magnetisation of the surface.