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Learn about designs, documents and diagrams related to human-computer interaction including processing and data handling, data flow diagrams (level 0 and level 1), flowcharts and user interface designs (visualisation and wireframe diagrams). Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 5.3 - Human Computer Interface Designs, Documents and Diagrams Watch on YouTube : Data flow diagrams Flowcharts Visualisation diagrams Wireframe diagrams There are four types of documents / diagrams you need to know that can be used to design human-computer interfaces : data flow diagrams (DFDs ), flowcharts , visualisation diagrams and wireframe designs . For each type of diagram , you need to know its components and conventions , when it is appropriate for use , and how to create it . Each diagram is also effective for different uses and you must be able to consider how specific diagrams can be made more effective . Human-Computer Interface Diagrams Data Flow Diagrams A data flow diagram (DFD ) is a visual representation of how data is transferred within a system or organisation . They do not show decision logic or sequencing , but focus on where data comes from , where it goes and how it is processed . DFDs are typically categorised into Level 0 and Level 1 formats, which differ based on complexity . Flowcharts A flowchart is a diagram that shows the sequence of steps in a process using specific symbols . Flowcharts can be used as a project planning tool (section 3.2 ) to visualise workflows , task order and decision-making paths . It is also useful as a human-computer interface diagram to show the steps and decisions users may take as they interact with the application . The video says ' 3.2d ' because flowcharts also appear in section 3.2 as a project planning tool . Visualisation Diagrams Visualisation diagrams are graphical representations used to show the layout , structure and appearance of a software application's interface . They're often used for planning , design and feedback purposes. Traditionally, they would be drawn on paper in pencil and annotated , but modern diagrams are mocked up on a computer so they can be easily shared with team members and clients . Wireframe Diagrams Wireframe diagrams are basic visual guides used to represent the structure and layout of a user interface (UI ) without any design styling . They focus on function , layout and interaction , not aesthetics . Wireframe diagrams are used in the early design stages to plan the UI layout before visual design begins. Q uesto's Q uestions 5.3 - Human Computer Interface Designs, Documents & Diagrams: 1. Explain what the purpose of data flow diagrams are, the difference between Level 0 and Level 1 and what makes them effective . [6 ] 2. Draw a wireframe diagram for the YouTube homepage . [3 ] 3. Explain how visualisation diagrams are created and how they can be made more effective . [ 5 ] The first type of flowchart , the ' flow process chart ', was developed by engineers Frank and Lillian Gilbreth in 1921 . The book (and original movie ) ' Cheaper by the Dozen ' is about this couple . D id Y ou K now? 5.2 - Visual Design Considerations Topic List 6.1 - Job Roles

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Learn about the different types of applications software including productivity programs, business tools and IDEs. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.2: Applications Software Exam Board: OCR Specification: 2016 - Unit 1 What is applications software? Don't confuse applications software and apps . Apps generally have a single purpose , such as a game like Angry Birds or the torch tool on a phone. Applications software can be used for a number of different functions depending on the user's needs and their purpose. Productivity Software This is general use software for completing a range of tasks accurately and efficiently . Key examples include word processors (e.g. Microsoft Word or Google Docs), presentation software (e.g. Microsoft PowerPoint or Google Slides) and web browsers (e.g. Microsoft Edge or Google Chrome). Email applications (e.g. Microsoft Outlook or Gmail) are beneficial to organisations because staff can send information to many customers at once which is a simpler and less costly method of communication than something like sending letters or leaflets in the mail. Emails can also include attachments of important documents and include multimedia elements like images and videos to make communication more interesting . Databases and Spreadsheets Database tables and spreadsheets can store both numerical and textual data ready for analysis . Examples include simple database tables and financial spreadsheets of a company's profits each year. Microsoft Access is an example of database software that uses tables of records and Microsoft Excel is an example of spreadsheet software . Data can be sorted numerically or alphabetically for both software types but graphs can be created from spreadsheets to visualise data . When using spreadsheets (or databases) records can be locked ('record locking' ) so that only one person can make edits to a specific record at any one time. Edits will be saved before unlocking the file. This will stop data being incorrectly overwritten and will ensure that the data in the spreadsheet is up-to-date, accurate and fit for purpose. Development Tools These are tools for programmers who are creating or modifying software . An integrated development environment ( IDE ) is software used to create , edit and debug (fix) programs . An IDE features a number of tools , including: A source code editor to type program code into. It may contain features such as error highlighting and automatic formatting . Because IDEs use high-level languages like Python or Java , a translator is required to convert the source code into machine code ( binary ) so that it can be understood and processed by the CPU . A compiler is a type of translator that converts instructions into machine code (binary) in one go . An interpreter is a type of translator that converts instructions into machine code (binary) line by line . A debugger is used to test code and display errors . Other development tools aid programmers with developing and maintaining websites and apps for phones / tablets. An advantage of databases over spreadsheets is that data can be atomised - meaning it can be stored in separate tables (e.g. one for patients and one for doctors ) with records linked through relationships . This minimises data redundancy (duplication ), meaning there is a lower chance of making errors , and it is easier to search through the table as each record will only appear once . A search through a database is called a 'query '. Business Software This is specialist software for businesses , often made bespoke for an organisation based on their needs . Types of business software: Project management software allows teams of workers to collaborate and split large projects into manageable tasks with clear deadlines and assigned roles . A management information system (MIS ) processes a large amount of data and organises it for use in decision-making and general data analysis . See more about an MIS in section 3.5 . Multimedia programs such as video editors or animation suites can be used to create high-quality videos with images , audio and video clips . Collaboration tools for businesses allow employees to share ideas and resources in real-time . Publishing software allows users to implement text and images into eye-catching designs such as posters , leaflets or static adverts to include on a website. Expert systems use large databases for automatic decision-making , often making use of AI to quickly solve complex problems . A healthcare example of an expert system is a medical diagnosis program that may suggest possible illnesses when a patient's symptoms are input . CAD / CAM One example of business software used for the design and manufacture of a product is CAD / CAM (C omputer-A ided D esign / C omputer-A ided M anufacturing). CAD is used to create highly detailed digital designs and CAM translates these designs into instructions for manufacturing machines to make the product physically. These software packages use 3D modelling and image rendering along with exact measurements to create precise designs ready to be manufactured . Engineers use them to design and make mechanical parts and architects use them to create detailed building models and blueprints . Q uesto's Q uestions 2.2 - Applications Software: 1. State four different kinds of productivity software and briefly describe how each could be used . For example: "Word processors can be used to type up a letter in an office or write an essay for school." [8 ] 2. Describe two differences between database and spreadsheet software. [2 ] 3a. What is an Integrated Development Environment ? [1 ] 3b. Describe three tools used in an IDE. [6 ] 4. Giving brief examples of how they can be used, state four different types of business software . [8 ] 5. Suggest how a website design company could use each of the three types of applications software (Productivity Software , Development Tools and Business Software ). [ 6 ] 2.1 - Types of Software Topic List 2.3 - Utility Software

Learn about how communication skills contribute to software application development, including verbal, written and questioning techniques. Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 6.2 - Communication Skills Watch on YouTube : Communication skills Developers working to create applications must be able to effectively communicate with team members , clients and users in a range of different ways . There are five communication skills you need to know: appropriate language , verbal , non-verbal , questioning techniques and written communication . You need to be aware of how each communication skill contributes to software application development and when they would be used appropriately by various job roles and in different stages of application development . Communication Skills Forms of Communication Appropriate language must be used to meet the needs of the audience by tailoring vocabulary , tone and technical detail to suit the client . Non-verbal communication includes body language , facial expressions , gestures , posture , eye contact and appearance . Question techniques have different goals , such as probing questions being used to explore detail and clarifying questions to check understanding . Verbal communication relates to spoken words and includes articulation , tone and pace , but also listening skills . Written communication is through emails , reports , documentation , messages and comments . It requires clarity , accuracy and professionalism . Q uesto's Q uestions 6.2 - Communication Skills: 1. Give examples of when written communication would be used in application development and by which job roles . [3 ] 2. Describe four different types of questions , with an example of each that relates to application development . [4 ] 3. Explain why effective non-verbal communication is important in application development . [ 3 ] Studies estimate that adults ask about 30 questions a day , whereas 4-year-olds ask on average 300 questions a day . D id Y ou K now? 6.1 - Job Roles Topic List

Learn how to create simple programs in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Formerly pynewbs.com. Follow the instructions in each section and try the practice tasks on every page . At the end of each section are larger problems to solve. Pyt hon Sections 0. Setting up Python Installing and Using Python 1. Printing and Variables a. Printing b. Comments c. Creating Variables d. Using Variables Section 1 Practice Tasks 2. Inputting Data a. Inputting Text b. Inputting Numbers Section 2 Practice Tasks 7. Subroutines a. Procedures b. Functions Section 7 Practice Tasks 8. Lists a. Using Lists b. 2D Lists c. Dictionaries Section 8 Practice Tasks 9. String Handling a. Basic String Handling b. Number Handling Section 9 Practice Tasks 3. Data Types & Calculations a. Data Types b. Simple Calculations Section 3 Practice Tasks 4. Selection a. If Statements b. Mathematical Operators ( & MOD / DIV) c. Logical Operators Section 4 Practice Tasks 5. Importing from Libraries a. Random b. Sleep c. Date & Time d. Colorama e. More Libraries (math) Section 5 Practice Tasks 6. Loops a. For Loops b. While Loops Section 6 Practice Tasks 10. File Handling a. Open & Write to Files b. Read & Search Files c. Remove & Edit Lines Section 10 Practice Tasks 11. User Interfaces a. Graphical User Interface 12. Authentication a. Error Handling Extended Tasks Extended Task 1 (Pork Pies) Extended Task 2 (Lottery) Extended Task 3 (Blackjack) Extended Task 4 (Vet Surgery) Extended Task 5 (Colour Collection) Extended Task 6 (Guess the Word) Extended Task 7 (Guess the Number)

Learn about applications, utility software, open source and closed source, translators including interpreters, compilers and assemblers, stages of compilation (lexical analysis, syntax analysis, code generation and optimisation) and linkers, loaders and libraries. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 2.2 - Applications Generation Specification: Computer Science H446 Watch on YouTube : Application software Utilities Open & closed source Translators Stages of compilation This topic explores key types of software and how they support computer systems and users . It explains different kinds of applications , utilities , translators and compares open and closed source software . Another important concept is compilation , with knowledge required of its different stages , as well as linkers , loaders and software libraries . Applications Software Applications software allows users to carry out productive or creative activities such as document editing , data analysis , communication or media creation . Common examples include word processors (e.g. Microsoft Word or Google Docs ), spreadsheets (e.g. Excel or Sheets ), database management systems (e.g. Access ), web browsers (e.g. Chrome or Safari ) and graphics editors (e.g. Photoshop ). Applications can be general-purpose , serving many uses , or special-purpose , created for a specific function like payroll or medical record management . YouTube video uploading soon Utilities Utility software is system software designed to maintain , optimise and manage a computer’s performance , often running in the background to support the operating system . Examples include security tools like an antivirus , backup , compressors , disk management utilities and defragmenters . Defragmentation is the process of reorganising files on a hard drive so that parts of each file are stored together in contiguous blocks , improving access speed . YouTube video uploading soon Open Source & Closed Source Open source software has its source code (the actual code written by its developers ) made publicly available , allowing users to view , modify and share it freely . An open source licence encourages collaboration , transparency and community-driven improvement . However, it may lack official technical support or guaranteed updates . Closed source software has its source code private , restricting modification and redistribution . It is usually sold commercially with paid licences , regular updates and dedicated technical support . Bug fixes and quality assurance are out of the user's control , being managed by the developer . Support may end without warning . YouTube video uploading soon Translators Translators are programs that convert source code written in one programming language into another form that the computer's CPU can understand - typically machine code (binary ). An assembler translates assembly language into machine code that the CPU can execute directly . An interpreter translates and executes high-level code in a line-by-line method, stopping when an error occurs . A compiler translates the entire high-level program into machine code before execution , producing an executable file . YouTube video uploading soon Stages of Compilation Compilation is a complicated process to convert high-level program code into machine code . It consists of four key stages : Lexical analysis breaks the source code into tokens , such as keywords , identifiers and symbols . In this stage unnecessary characters like spaces or comments are removed . Syntax analysis checks that the token sequence follows the grammatical rules of the programming language , building an abstract syntax tree . Code generation converts the syntax tree or intermediate code into machine code the CPU can understand . Code optimisation improves the efficiency of the generated code , for example by reducing redundant instructions or improving execution speed . Compilation also requires additional programs such as a linker and loader and the use of libraries . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Applications: database, word processor, web browser, graphics manipulation, spreadsheet software, presentation software Utilities: defragmentation, system cleanup, file manager, device driver, security tools Open & Closed Source: source code, open source, closed source Translators: assembler, interpreters, compiler, machine code Stages of Compilation: lexical analysis, token, syntax analysis, abstract syntax tree, code generation, code optimisation, library, linker, static linking, dynamic linking, loader D id Y ou K now? Grace Hopper , a US Navy rear admiral , is credited with creating one of the first compilers in 1952 and coining the term ' compiler '. She also helped develop the languages FLOW-MATIC and later COBOL , which is still used today . 2.1 - Systems Software A-Level Topics 2.3 Software Development

This page contains topics from the 2016 Eduqas / WJEC that are not included in the 2020 Eduqas / WJEC specification. Topics from the 2016 Eduqas Specification This page contains information from the 2016 Eduqas specification that was removed for the 2020 specification. Quick Links: Buses & Instruction Sets (RISC & CISC) Protocols (IMAP & POP3) Network Devices (Gateway) Human-Computer Interaction (Command-Line Interface, Touch-Sensitive Interface, Menu-Driven Interface, Voice-Driven Interface) Cyber Attacks (Dictionary Attack, Buffer Overflow, Human Weakness) Software Protection (Secure by Design, Too Many Permissions, Scripting Restrictions, Validation with Parameters) Data Policies (Acceptable Use Policy, Disaster Recovery, Cookies) Environmental Issues (Tips to Reduce Waste, Positive Impacts of Technology) Object Oriented Programming (Greenfoot and Java) Programming Topics (Assembly Language, HTML, Greenfoot) Buses Buses & Instruction Sets Buses Data is transferred within a computer system along pathways called buses . There are three types of bus: Address Bus Data Bus Control Bus Sends a memory address of where data is stored. The address is sent from the CPU to RAM in the FDE cycle. Transfers data between components. Data is sent both ways . Sends control signals from the control unit to other components of the system. Status signals are sent back to the CPU. An instruction set is a list of all the instructions that a CPU can process as part of the FDE cycle . CPUs can have different sets of instructions that they can perform based on their function. The two most common instruction sets are the simpler RISC (Reduced Instruction Set Computer ) and more complicated CISC (Complex Instruction Set Computer ). Instruction Sets Reduced Instruction Set Computer (RISC) Complex Instruction Set Computer (CISC) Complexity RISC has fewer instructions than CISC and is therefore slower for carrying out complex commands but quick for basic tasks . CISC has more complex instructions available and can therefore perform complicated tasks . Cost RISC is generally cheaper to mass produce because less circuitry is required for the smaller instruction set. CISC CPUs are generally more expensive because they require more circuitry to operate. Power RISC CPUs are designed to use less power and run without dedicated cooling systems (like fans) so that they can be used in devices like smartphones . Because CISC CPUs require more circuitry this means that they generate more heat and may require a fan . CISC CPUs therefore are commonly used in desktop computers . Clock Speed RISC CPUs run at lower clock speeds than CISC CPUs. They can perform simpler tasks more quickly than CISC, but are generally not used to carry out complex instructions . CISC CPUs run at higher clock speeds than RISC CPUs. They can perform complex tasks more quickly than RISC. Protocols Protocols POP3 ( Post Office Protocol 3 ) and IMAP (Internet Message Access Protocol ) are both protocols for receiving and storing emails from a mail server. Gateway Network Devices Gateway A gateway joins together two networks that use different base protocols . For example, a gateway could link together a LAN to a WAN . HCI Human - Computer Interaction Command-Line Interface Touch-Sensitive Interface Other types of user interface do exist, such as a command-line interface (CLI ). This type of interface is entirely text-based and requires users to interact with the system by typing commands . This is a complicated process and mistakes could easily accidentally delete data. There are many commands to learn so only experts who have been trained t o learn this interface will be able to efficiently make use of it. Another type of user interface is a touch-sensitive interface , used with smartphones and tablets . A human interacts with the device by pressing on a touchscreen , making it very intuitive and suitable for most users without training. Touch-sensitive interfaces may not work with dirty or wet fingers and it will take longer to write text compared to using a keyboard. Menu-Driven Interface A menu-driven interface displays data in a series of linked menus . Examples include cash machines (ATMs) and old iPods . This type of interface is generally user friendly and easy to use as commands do not need to be memorised. However it can be annoying to find specific data through a large number of menus without a search feature. Voice-Driven Interface A voice-driven interface can be controlled by speaking commands aloud to a listening device. Examples include Amazon's Alexa devices, Apple's Siri technology and Google Home . This interface is intuitive , can be used hands-free and helps to speed up processes . However commands may be misheard or limited in what can be performed. Cyber Attacks Cyber Attacks Dictionary Password Attack This uses a file containing every word in the dictionary and cycles through them all. This method is relatively easy to program but will only break the simplest passwords . Buffer Overflow Attack A buffer is a temporary storage location . A buffer overflow attack causes a program to try to store more data in a buffer than it can hold which can lead to adjacent memory locations being overwritten . An attacker can use the buffer overflow to insert malicious code to change data or steal confidential data . Human Weakness The biggest weakness in online security is often not the systems in place but carelessness or mistakes made by humans . Social engineering means to trick others into revealing their personal data by posing as a trusted source . For example, impersonating an IT technician via email and asking to send a username and password. Humans can accidentally compromise data by downloading malicious files or being unsafe online, like using the same password for multiple different accounts. Attackers can access unauthorised information in person by shoulder surfing and watching them as they enter sensitive data such as a PIN or password. Software Protection Software Protection The following methods of protection are considered in the design, testing and creation stages of developing software . Secure by Design This method puts security as the most important concept when creating and designing software . By focusing on security when designing software there should be less need for later updates and patches and attacks are less likely to succeed . Too Many Permissions Apps require permission to use device features (such as the camera or microphone of a smartphone) when they are downloaded. Programmers should only request permission for features that the software requires . Some malicious apps steal data or spy on users - and the worst part is that you've given permission for it to do it! Users can avoid suspicious apps by reading reviews, checking there are no unnecessary permission requests , only downloading the software you need / will use and uninstall apps if permissions change . Scripting Restrictions A script is a set of instructions executed on a website. For example, Facebook uses a JavaScript script to post a status and another to read your private messages. The Same Origin Policy (SOP) is a security precaution that prevents websites from using scripts on other sites that you have open . For example, if you are using JavaScript to post a status on Facebook then visit an infected site, that site can't also use JavaScript to access your Facebook data, because even though they both use JavaScript, they are from a different origin . Without SOP an infected website could access personal data or infect a computer with malware by maliciously using the same scripts as other websites you have used . Programmers should set scripting restrictions when creating websites. Validation with Parameters A parameter is a measure that is used when validating data , it is usually a range or limit. For example, the parameters of a length check may be whether the data is between 1 and 10 characters . Programmers must ensure validation is used on websites with suitable parameters to prevent attacks such as an SQL injection. Data Policies Data Policies Data policies are written documents that clearly define how data should be managed in an organisation. It is important that all employees stick to these policies and requirements so that data is kept safe and can be replaced if lost or corrupted. The following methods are examples of common data policies. Acceptable Use Policy (AUP) Workplaces and schools often require people to sign an acceptable use policy (AUP) before being allowed to use the network. It is a list of rules and expected behaviour that users must follow when using the computer systems. Typical rules include: Which websites are off-limits (such as social media or gambling sites), Download permissions (such as who can download and install software) Email communication (such as appropriate language). Punishments if rules of the AUP are broken. The AUP is sometimes known as a Code of Conduct . This is an example of a formal code of practice , with written rules and clear expectations . An informal code of practice would not be officially written down , such as personal habits and preferences (e.g. email layout or desk organisation). Disaster Recovery With important data often stored on a computer network, it is absolutely vital that a detailed and effective disaster recovery policy is in place in the event of data being lost due to an unexpected disaster. Disasters include natural disasters (e.g. fire, flood, lightning), hardware failure (e.g. power supply unit failing), software failure (e.g. virus damage) and malicious damage (e.g. hacking). There are three clear parts to a disaster recovery policy: Before the disaster: All of the possible risks should be analysed to spot if there are any weaknesses in preparation. Preventative measures should be taken after the analysis, such as making rooms flood-proof or storing important data at a different location . Staff training should take place to inform employees what should happen in the event of a disaster. During the disaster: The staff response is very important – employees should follow their training and ensure that data is protected and appropriate measures are put in place. Contingency plans should be implemented while the disaster is taking place, such as uploading recent data to cloud storage or securing backups in a safe room and using alternative equipment until the disaster is over. After the disaster: Recovery measures should be followed, such as using backups to repopulate computer systems. Replacement hardware needs to be purchased for equipment that is corrupted or destroyed. Software needs to be reinstalled on the new hardware. Disaster recovery policies should also be updated and improved . Cookies A cookie is a small piece of data that is stored by websites when you visit them. They allow the website to identify the user and are often used to speed up processes , such as: Automatic login (by saving account details) Save items into a basket (such as pizza delivery sites) Display adverts related to your previous search terms . Although they can be used to save time, some argue that cookies can be intrusive and store too much information. Environmental Issues Environmental Issues Tips to Reduce Waste Turn off computers , monitors and other connected devices when not in use . Adjust power options to help minimise power consumption. Devices with the Energy Star sticker use between 30% and 70% less electricity than usual. Repair older devices rather than throwing them away. Ink jet printers use up to 95% less energy than laser jets. Think twice about printing paper, don't waste ink and remember to recycle paper . Positive Environmental Impacts Communication advancements (such as video messengers) reduces pollution as people do not have to travel to speak to each other. This is especially beneficial in business - workers can talk from the office and do not need to catch a plane to speak. Smart devices can monitor usage and reduce energy waste - such as smart air conditioners and home security systems. Collaboration software (such as cloud-based technology and Google Docs) allows experts to work together and share data. The internet and research databases allows scientists to study the environment more efficiently. Documents can be viewed on a screen rather than printed out - books and newspaper articles can be read on kindles / tablets saving paper and ink . New materials and more environmentally-friendly processes have been developed thanks to increased technology and research. Object Oriented Programming Object-Oriented Programming (OOP) Java is an example of object-oriented programming (OOP) where a programmer is able to code objects that can be visually placed onto a background. Greenfoot is an IDE for Java . Superclass A class from which other 'subclasses' will inherit characteristics ; e.g. hippos, crocodiles and polar bears will inherit properties from the Animals superclass. Object A single object from a class ; e.g. one crocodile object from the Crocodile class. Class A set of objects which share the same properties ; e.g. all PolarBears will behave in a similar way. Comment Two / symbols will allow you to write a comment to explain the code . Method A series of instructions that an object will follow . The act() method will loop in Greenfoot when the play button is pressed. Programming Programming Topics Variable Scope & Lifetime The scope of a variable refers to the parts of the program where the variable can be viewed and used , e.g. a variable with global scope can be accessed anywhere in the program . The lifetime of a variable is the amount of time the variable is stored in memory and therefore can be used , e.g. local variables can only be accessed throughout the subroutine they are created in. Programming Languages: Assembly Language HTML Greenfoot Theory Topics

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 2 Lottery 17 8 4 13 20 Create a program to simulate a lottery draw. First, create an appropriate print line to welcome the user to your lottery draw. Then let the user enter five numbers between 1 and 20. Next, randomise five numbers between 1 and 20. Check to see how many numbers match and output an appropriate response for each scenario (e.g. “You have not matched any numbers, better luck next time!”) Once you have made the base program implement subroutines and lists . Make it as efficient as possible and professional-looking. Use pauses to reveal each number one at a time like a real lottery draw to build suspense. For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Example solution: Helpful reminders for this task: Inputting Numbers Random Numbers Logical Operators Subroutines ⬅ Extended Task 1 (Pork Pies) Extended Task 3 (Blackjack) ➡

Learn how to use if statements in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 4a - If Statements If Statements Selection is one of three constructs of programming , along with Sequence (logical order) and Iteration (loops). An if statement is a conditional statement that performs a specific action based on conditional values. Essentially, if thing A is true , then thing B will happen . If the user answers yes to the window question, then an appropriate statement is printed. Double equals stands for ‘is equal to ‘. The colon stands for THEN and the line after an if statement must be indented (press tab key once). answer = input ( "Is the window open? " ) if answer == "yes" : print ( "It's chilly in here!" ) Is the window open? yes It's chilly in here! But what if the window is not open? At the moment nothing will happen if you type no: Is the window open? no The elif command stands for else if . Essentially: If thing A is true then do thing B, else if thing C is true then do thing D: But what about any other answer than yes or no? The else command will submit a response if the value is anything else. The if and elif commands have a colon at the end, but else has it at the start. Also, else does not need to be on a new line. answer = input ( "Is the window open? " ) if answer == "yes" : print ( "It's chilly in here!" ) elif answer == "no" : print ( "It's quite hot in here!" ) answer = input ( "Is the window open? " ) if answer == "yes" : print ( "It's chilly in here!" ) elif answer == "no" : print ( "It's quite hot in here!" ) else : print ( "I'm not sure what you mean." ) Is the window open? no It's quite hot in here! Is the window open? banana I'm not sure what you mean. If Statements Task 1 ( Left or Right?) Use an input line to ask the user whether they want to turn left or right . Print a sentence of your choice if they chose left and a different sentence if they chose right . Include an else statement in case the user doesn't input left or right. Example solutions: There is a path ahead. Do you turn left or right? left The path turns and twists until it reaches a cliff. Dead end! There is a path ahead. Do you turn left or right? right A snake slithers across the path and bites your leg. Oh no! There is a path ahead. Do you turn left or right? backwards That's not an option! Nested If Statements Complex programs may require you to have if statements within if statements - when programming, one thing inside another is known as nesting . You must make sure that the related if , elif and else statements line up with each other . Use the tab key to indent a line. outer if inner if weather = input ( "What is the weather like today? " ) if weather == "sunny" : sunny = input ( "How hot is it? " ) if sunny == "very hot" : print ( "Take some sunglasses with you!" ) elif sunny == "cool" : print ( "Maybe take a jacket just in case?" ) else : print ( "Enjoy the sunshine!" ) elif weather == "rainy" : print ( "Take an umbrella!" ) else : print ( "Have a good day!" ) = What is the weather like today? rainy Take an umbrella! = What is the weather like today? sunny How hot is it? cool Maybe take a jacket just in case? = What is the weather like today? snowy Have a good day! = What is the weather like today? sunny How hot is it? very hot Take some sunglasses with you! If Statements Task 2 ( Nested Ifs) Use the weather program above as an example to help you write your own program with a nested if for at least one option. Be careful to have your nested if's if, elif and else statements in line with each other. Your program doesn't have to be about juice. Example solutions: Would you like orange, apple or tomato juice? orange Would you like your orange juice smooth or with bits? smooth One smooth orange juice coming up! Would you like orange, apple or tomato juice? orange Would you like your orange juice smooth or with bits? bits A pulpy orange juice is on its way! Would you like orange, apple or tomato juice? tomato Yuck, you can't be serious? Using Selection with Numbers Comparison operators such as > (greater than ) > = (greater than or equal to ) < (less than ) and < = (less than or equal to ) can be used with if statements. Logical operators such as and and or can also be used - more about them in section 4c . When comparing a variable's value to a specific number, such as 50, don't forget to use double equals ( == ) . Python Comparison Operators score = int ( input ( "Enter the maths test score: " )) if score == 50: print ( "You scored top marks!" ) elif score >= 40 and score < 50: print ( "You scored a great grade!" ) elif score >= 20 and score < 40: print ( "You did okay in the test." ) else : print ( "You have to try harder next time!" ) = Enter the maths test score: 50 You scored top marks! = Enter the maths test score: 43 You scored a great grade! = Enter the maths test score: 20 You did okay in the test. = Enter the maths test score: 13 You have to try harder next time! If Statements Task 3 ( Fastest lap) A racing video game has a challenging track that players try to get a quick lap on. The current fastest lap time is 37 seconds . Ask the player to enter their lap time and print a response based on their input . You need individual responses for the following inputs: Faster than 37 seconds. Between 37 seconds and 59 seconds. Between 60 seconds and 90 seconds. Slower than 90 seconds. Example solutions: Enter your lap time: 35 You have set a new record!!! Enter your lap time: 59 You did well this time! Enter your lap time: 83 A little bit slow this time! Enter your lap time: 110 Were you even trying!?! Hurry up! Not Equal To The opposite of equal to ( == ) is not equal to ( != ). != is often used with while loops to repeat code while an input is not what is expected , for example repeatedly asking for a password while the input is not equal to "fluffythecat123". The code below uses != for an incorrect answer (although it could easily be re-written to use == for a correct answer). answer = input ( "What is the capital of Eritrea? " ) if answer != "Asmara" : print ( "That is incorrect! It is Asmara." ) else : print ( "You got it right!" ) = What is the capital of Eritrea? Asmara You got it right! = What is the capital of Eritrea? Windhoek That is incorrect! It is Asmara. If Statements Task 4 ( True or False? ) Come up with your own true or false question that the user has to respond to. Depending on their answer , print whether they got it right or wrong . You may want to use an if statement with == for a correct answer or != for an incorrect answer , there's multiple ways to write this program. Example solutions: There are 140 million miles between Earth and Mars. TRUE or FALSE? TRUE That is correct! It is really that far! There are 140 million miles between Earth and Mars. TRUE or FALSE? FALSE You got it wrong, there really are 140 million miles between us! ⬅ Section 3 Practice Tasks 4b - Mathematical Operators ➡

Learn about lossy and lossless compression and the lossless compression algorithms run-length encoding and dictionary coding. This topic also covers symmetric and asymmetric encryption and the uses of hashing. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.1 - Compression, Encryption and Hashing Specification: Computer Science H446 Watch on YouTube : Lossy & Lossless Compression Lossless Compression Algorithms Encryption Hashing Lossy vs Lossless Compression Compression is the process of reducing the size of a file so it takes up less storage space and can be transmitted more quickly over a network . It works by encoding data more efficiently or removing unnecessary information . The main benefits of compression include faster file transfer speeds , reduced storage requirements and improved performance when streaming data . Lossy compression permanently removes some data that is less important to human perception , such as subtle sounds or image details , resulting in smaller file sizes but slightly lower quality . Lossless compression reduces file size without losing any data , allowing the original file to be perfectly restored after it is decompressed . YouTube video uploading soon Lossless Compression Algorithms There are two types of lossless compression that you need to know: Run-Length Encoding (RLE ) is a simple form of lossless compression that reduces file size by storing repeating data as a single value and a count . For example, a sequence like AAAAABBBCCCC could be stored as A5B3C4 , saving space in files with many repeated elements , such as pixels in images . Dictionary Encoding replaces repeating patterns of data with shorter codes that reference entries in a dictionary . The dictionary stores common sequences once , and each repetition is replaced by a shorter reference , making it efficient for text and other data with recurring patterns . YouTube video uploading soon Encryption Encryption is the process of converting readable data (plaintext ) into an unreadable form (ciphertext ) to prevent unauthorised access . It ensures the confidentiality and security of information during storage or transmission . There are two key types of encryption : Symmetric encryption uses the same key for both encryption and decryption , meaning the sender and receiver must share the key securely . It is fast and efficient , making it suitable for encrypting large amounts of data . However, key distribution is a major risk if the key is intercepted . Asymmetric encryption uses a pair of keys - a public key for encryption and a private key for decryption . It is more secure for communication but slower due to complex mathematical processes . Asymmetric encryption is often used to exchange symmetric keys securely before data transfer . YouTube video uploading soon Hashing Hashing is the process of applying a mathematical function (hash function ) to data to produce a fixed-size value , known as a hash . It is a one-way process , meaning the original data cannot be reconstructed from the hash . Hashing is commonly used for data integrity checks , password storage and digital signatures . Even a tiny change in the input data produces a completely different hash , making it useful for detecting tampering or corruption . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Compression: lossy compression, lossless compression, run-length encoding, dictionary encoding Encryption: plaintext, ciphertext, key, symmetric encryption, asymmetric encryption Hashing: hash function, hash D id Y ou K now? Alan Turing and his team used pattern recognition to analyse recurring sequences in encrypted German messages , helping to break the Enigma code , which was a major factor in the Allies’ victory in World War II . 2.4 - Programming Languages A-Level Topics 3.2 - Databases

Learn about networking standards and the seven layers of the Open Systems Interconnected (OSI) model - Application, Presentation, Session, Transport, Network, Data Link and Physical. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.6: 7-Layer OSI Model Exam Board: Eduqas / WJEC Specification: 2020 + What are networking standards? Networking standards are rules that allow computer systems to communicate across networks . Standards have been created to ensure devices can exchange data and work together . What is the 7-layer OSI Model? The OSI ( Open Systems Interconnection ) model is split into 7 layers . The model is used to visualise the different parts of a network as each of the seven layers has a specific role . Splitting a network design into layers is beneficial to programmers as it simplifies design , making it easier to modify and use . Each layer has a certain purpose and is associated with different protocols . The seven layers are explained below: 7 Allows humans and software applications to use the network e.g. browsers (HTTP /HTTPS ) and email (SMTP ) and file transfer (FTP ). 6 The purpose of the presentation layer is to display data in a standard format that other devices can accept and understand . 5 The session layer establishes a connection between computers allowing data to be sent between them. Data can be synchronised in each session to allow for efficient data transfer . 4 TCP breaks the data down into data packets . This layer makes sure the data is sent and received in the correct order and reassembled at the destination without errors. 3 IP is responsible for addressing and routing data packets . The optimal route for the data to take is calculated in this layer. Also known as the 'Internet Layer '. 2 Ethernet sets out the format of data packets . This layer handles transmission errors and passes data to the physical layer . 1 This layer converts the data packets into bits so they can be transferred across a physical connection using routers and switches . Q uesto's Q uestions 3.6 - 7-Layer OSI Model: 1a. What are networking standards ? [ 2 ] 1b. Describe why network designs are split into layers . [ 2 ] 2. Create a diagram similar to the one above and describe each layer of the OSI Model. [ 14 ] 3. Look at the statements below and name the layer that is being described: a. This layer ensures data packets are sent and received correctly. b. This layer checks for errors in transmission and sets out the data packet format. c. This layer displays data in a format that can be understood. d. This layer allows software like web browsers to interact with the network. e. This layer transfers bits across a connection using routers. f. This layer establishes a connection between computer systems. g. This layer uses addresses to ensure data packets take the correct route. [ 7 ] 3.5 - Protocols Theory Topics 3.7 - The Internet

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 6 'Guess the Word' Game Create a Python program similar to the hit New York Times puzzle game Wordle . Allow the user to make guesses to match the randomly chosen hidden word , stopping when they get it correct. You can download a list of 5-letter words on this page. You will need to read in each line of the list and randomly select one - don’t forget to import the random library . Check if each letter of the user’s inputted word is in the randomly selected word . If you are using an IDE like Replit you can use the colorama library and the Fore command to turn the text: Green if the letter is in the correct position . Red if the letter is not in the selected word . Yellow if the letter is in the selected word but not in the correct position . Add your own flair and additional features to your program as an extension, including limiting the number of guesses and recording how many attempts it took to get the correct answer. Download a file of 534 5-letter words: For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Reminders for this task: You will need a while loop to repeatedly allows the user to enter words until they match the correct word. Section 10 will help you to open, write and r ead from files . Download the file of 5-letter words from the link above. You will need to randomly select a word from the file. The choice command will help. Selection will be necessary to check if each letter in the inputted word matches the letter in the same position in the correct word. String handling is needed to select specific letters in a string. You will need to use .rstrip() on the selected line (word) that you have randomly chosen from the file. This removes any hidden characters that may interfere with checking if it is equal to the inputted word. There are multiple ways to approach this program, and your solution might look different from the example. Break the problem down and focus on one part at a time. Example solution: The word the user enters should be checked , letter by letter , against the letters in the same position in the randomly chosen correct word . Remember that the first letter in a word has the position 0 , not 1. Below is an example of some incomplete code you may wish to use in your solution. ⬅ Extended Task 5 (Colour Collection) Extended Task 7 (Number Game) ➡