Search CSNewbs

Learn about algorithms for data structures such as stacks, queues, linked lists and trees, as well as how to traverse trees with depth-first and breadth-first traversal methods. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 3.1e - Data Structure Algorithms Watch on YouTube : Stacks Queues Linked Lists Trees Tree traversal Being able to read , trace and write code for data structure algorithms (stacks , queues , linked lists and trees ) is vital. Stacks A stack stores data in a last in , first out (LIFO ) order, meaning the most recently added item is the first one to be removed . It works much like a stack of plates - you can only add or remove from the top . Two integral functions are push and pop . The push operation adds (or “pushes”) a new item onto the top of the stack . The pop operation removes (or “pops”) the item from the top of the stack . Stacks are commonly used in undo features , function calls and expression evaluation , where tracking the most recent item first is important . YouTube video uploading soon Queues A queue stores items in a first in , first out (FIFO ) order, meaning the first item added is the first one removed . New items are added at the rear of the queue using an enqueue operation, and items are removed from the front using a dequeue operation. Queues are often used in task scheduling , print spooling and data buffering , where operations must occur in the same order they were requested . YouTube video uploading soon Linked Lists A linked list is a dynamic data structure made up of a series of elements called nodes , where each node contains data and a pointer to the next node in the sequence . Unlike arrays, linked lists do not store elements in contiguous memory locations , making it easy to insert or delete items without having to shift other elements . The head is the first node in the list , and the last node usually points to null , indicating the end of the list . YouTube video uploading soon Trees A tree is a hierarchical data structure made up of nodes connected by branches , starting from a single root node . Each node can have child nodes , and nodes without children are called leaf nodes . Trees are useful for representing data with natural hierarchies , such as file systems or organisational charts . A binary search tree is a special type of tree where each node has at most two children - a left and a right . All values in the left subtree are smaller than the parent node , and all values in the right subtree are larger . This structure allows for efficient searching , insertion and deletion of data , often much faster than in lists or arrays . YouTube video uploading soon Tree Traversal 'Tree traversal ' refers to the method used to visit every node in a tree data structure in a specific , organised order . Depth-first (also called post-order ) traversal explores a tree by moving as far down one branch as possible before backtracking , visiting nodes in a deep , top-to-bottom manner . It uses a stack to keep track of nodes still to explore , pushing new branches onto the stack and popping them when backtracking . Breadth-first traversal explores the tree level by level , visiting all nodes on one level before moving down to the next . It uses a queue to hold nodes in the order they should be visited , ensuring the traversal expands outward evenly from the root . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Stacks and Queues: stack, queue, last in first out (LIFO), first in first out (FIFO), push, pop, enqueue, dequeue, pointer Linked Lists: linked list, null Trees: tree, binary tree, binary search tree, root node, branch, depth-first traversal, breadth-first traversal D id Y ou K now? Spotify playlists work like linked lists because each song links to the next , allowing tracks to be added , removed or reordered instantly without reshuffling the whole playlist. This makes the app fast and efficient even when handling huge playlists with thousands of songs . 3.1a-d - Algorithm Complexity A-Level Topics 3.1f - Standard Algorithms

Learn about how information can be classified into groups including private, public, sensitive and confidential. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 2.2 - Information Classification Exam Board: OCR Specification: 2016 - Unit 2 Information can be classified into different groups . Some data may fall into more than one classification. Sensitive Information Description: Information that should be protected from being publicly released as it could harm the safety or privacy of an organisation or an individual . Examples: Medical data that could be embarrassing to an individual if released. Financial data that will negatively impact the company if made public to competitors. Non-Sensitive Information Description: Information that can be released publicly with no fear of negative consequence . Examples: Store information including shop addresses , opening hours and the names of senior managers. Product information including prices , online reviews and general availability . Private Information Description: Private information relates to an individual and it should not be shared with anyone else without the data subject's permission . Private information is protected by the Data Protection Act and would need to be stored securely so it cannot be accessed without authorisation. Examples: Home addresses, contact information, birth dates and banking details . Employee data such as linked bank accounts and addresses. Public Information Description: Released to the public and can therefore be seen by anyone . Public information is non-sensitive . Examples: Social media usernames, posts and shared images. Public business information including addresses, promotional material and opening times. A government report like the national census every ten years. Personal Information Description: Identifiable data about a specific individual . Examples: Full name , date of birth , gender , marital status, medical history, sexual orientation and voting history. Business Information Description: Any kind of data about a specific business. This information could be public or private. Examples: Address of its headquarters Financial data or employee details. Annual sales figures . Confidential Information Description: Private data that is more restricted than sensitive information , with access limited to only those who need to know. Examples: Doctor / therapist notes Business Profits and losses Trade secrets Classified Information Description: Highly sensitive information stored by a government institution , requiring the highest levels of restricted access . Access is usually restricted by law and only viewable by authorised individuals or groups. In the UK there are three levels of classified information: OFFICIAL , SECRET and TOP SECRET . Examples: Military data Terrorism precautions Crime scene reports Anonymised Information Description: Anonymisation removes personally identifiable data from information so that an individual cannot be identified . This allows the information to be used in much wider context without running the risk of legal action. Examples: Partially anonymised information - where some of the personal information has been removed and replaced by a symbol . Completely anonymised information - where all identifiable data has been removed . Bank details are often partially or completely anonymised. A partially anonymised credit card number might be listed as: **** - **** - **** - 7427 Problems with anonymising data include: If sensitive data is not anonymised enough and the person can be identified . Useful information could be lost if too much data is anonymised . The public could lose trust in an organisation if data is insufficiently anonymised . Q uesto's Q uestions 2.2 - Information Classification: 1. Describe each type of information classification and give at least two examples : a. Sensitive information [3 ] b. Non-Sensitive information [3 ] c. Private information [3 ] d. Public information [3 ] e. Business information [3 ] f. Confidential information [3 ] g. Classified information [3 ] h. Anonymised information (partial and complete) [6 ] 2. State which classification(s) the following pieces of information would be categorised as. It might fit into more than one category. a. Shop opening times [1 ] b. Medical history [1 ] c. Twitter username [1 ] d. Crime scene report [1 ] 3. Describe three problems that organisations should consider when anonymising data . [6 ] 2.1 - Information Styles Topic List 2.3 - Quality of Information

Learn about defensive design considerations including validation checks, verification, anticipating misuse, maintainable code, authentication and input sanitisation. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 3.1: Defensive Design Exam Board: OCR Specification: J277 Watch on YouTube : Defensive Design Validation Checks Maintainability Defensive Design Considerations There are several things to consider when creating a program that is secure and robust , including: Anticipating Misuse Planning ahead to take steps against potential misuse (e.g the app X prevents the same tweet sent twice in a row as it might be spam ). Input Sanitisation Checking and cleaning up data that has been input , (e.g. removing special characters to prevent a SQL injection ). Validation Checking whether input data follows specific criteria and should be accepted (e.g. a length check on a password). Verification Checking whether data that has been entered is correct (e.g. double entry ). Authentication Ensuring only authorised users can gain access to a system (e.g. usernames and strong passwords ) . Maintainable code Allowing other programmers to easily read and quickly understand code that has been written (e.g. using comments , indentation and appropriate variable names ). Input Validation Validation is a process to check that data is reasonable or sensible before it is accepted . Range Check Checks data is within a certain range . Age: 34 203 Type Check Checks data is a certain data type . Height (in cm): 182 Two metres Format Check Checks data is entered in a certain way . Date of Birth (DD/MM/YYYY) 25/03/2011 25th March 11 Presence Check Checks that data has actually been entered and not left blank . Password: fluffythecat123 Lookup Table A table of acceptable entries , also known as a list . Length Check Checks the length of the input is within a certain amount. Telephone Number 08323877319 07383 Maintainability Programs should be written in a way that makes maintaining and understanding them as straightforward as possible. Examples of making a program maintainable include: Using subprograms to reuse code and make them easier to test . This is called modularisation . Appropriate variable names , using a naming convention , ensure the purpose of a variable is immediately understood. Using indentation to improve readability and clearly show each ‘block’ of code. Comments enable a programmer to understand the purpose of each line of code. Crucial when working in a team . Using constants is another method of improving maintainability. This keeps the program code consistent , which makes it easier to read and debug a program. Q uesto's Q uestions 3.1 - Defensive Design: 1. Describe the different considerations a programmer should make for a defensive design . [ 6 ] 2. Describe the each validation check and give a suitable example . [ 12 ] 3. Explain the different ways a program can be maintained . [ 5 ] 2.3 Additional Programming Theory Topics 3.2 - Testing

Learn how to create and use dictionaries in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 8C - Dictionaries Creating a Dictionary Dictionaries are used in Python to link items of data together . The example on this page uses a footballer dictionary which links a player with a team they played for. To define a dictionary, use curly brackets { } and separate linked data with a colon . A dictionary can be written on one line but the method below makes it easier to read: Printing Data from a Dictionary The first part of the linked data in a dictionary is called the key (e.g. each footballer in my example above). The second part of the linked data in a dictionary is called the value (e.g. each team). Example: key : value "Harry Kane" : "Tottenham Hotspur" A for loop can be used to cycle through each set of keys and values in the dictionary: Practice Task 1 a) Create a dictionary of your teachers and the subject they teach. b) Print their name and the subject they teach on each line. Example solution: Adding and Removing Data from a Dictionary Data can be added to a dictionary by stating the new key and value . You must use square brackets - [ ] The new data will be added to the end of the dictionary. You can print the whole dictionary to see any changes - e.g. print(playerdictionary) Data can be removed from a dictionary by stating the new key to remove in a pop command. You can print the whole dictionary to see any changes - e.g. print(playerdictionary) The whole dictionary can be cleared (reset to blank) using the clear command. Practice Task 2 a) Ask the user to enter a new teacher and their subject. b) Ask the user to remove a teacher. c) Print the list of teachers and check the new teacher has been added and the other one removed. Example solution: Searching Through a Dictionary An if statement can be used to check if a specific key is in a dictionary. If the key is in the dictionary then a message can be displayed using the key and the value . Otherwise, an else statement can output an appropriate response. To search for a value in a dictionary a for loop should be used to cycle through each key . If the value of each key matches the value that is being searched for then it will be printed. Practice Task 3 a) Create a search that allows a user to enter a teacher's name and prints the subject that they teach. b) Include an else statement to print a response if a teacher is not in the dictionary. Example solution: Changing Data & Copying a Dictionary The way to change values is similar to adding new data. The first input below is to determine the key and the second input determines the new value to be changed to. The copy command is used to make a duplicate of a dictionary . Practice Task 4 a) Create a copy of your teacher dictionary. b) Allow the user to enter a teacher and a new subject that they teach. c) Print the copy of the dictionary with the new values. Example solution: Using a Dictionary to Make a Game The code below is used to make a puzzle game where the user has to type in a footballer and the team they played for. I have added comments to explain the different parts of the code. A separate list has been created at the start to store the names of keys (players) that been correctly guessed . A while loop is used to constantly ask the user for players and teams. When they have guessed all 10 players (and the correct list reaches 10 ) the loop breaks and the game end. Instead of a further practice task here, Task 6 of the Section 8 Practice tasks page challenges you to make a similar game using a dictionary. ⬅ 8b - 2D Lists Section 8 Practice Tasks ➡

Learn how to link to other websites by using the anchor tag. 4. Hyperlinks HTML Guide Watch on YouTube: A hyperlink is a link to another web page . In this section, you will link your page to a real website, like Wikipedia. Hyperlinks require the anchor tags and Copy a URL Firstly you need to copy the full web address of the web page that you would like to link your page to. Choose an appropriate web page that relates to your chosen topic. Create the Anchor Tag 4. Close the start of the tag . 1. Open the start of the tag . 2. Type href (stands for hypertext reference ). 3. Paste the URL inside speech marks . 5. Type the text you want the user to click on . 6. Time to close the tag . When you save your webpage and run it in a browser you will be able to click highlighted text to open the website you have chosen. Add at least three different hyperlinks to your webpage. Try to add the 2nd & 3rd links without looking at this page - practise makes perfect. Add a Hyperlink within a Sentence You can also create an anchor tag within a sentence. Hyperlinks are important to link webpages together. Next is time for adding pictures! Either change one of your previous hyperlinks to be in the middle of a sentence or create a new one. 3. Text Tags HTML Guide 5. Images

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 3 Hi, Susanna here, I want to make a blackjack-like program that I can play for fun at home in between revising for Computer Science. The aim of my blackjack game is to get as close to 21 as possible with the most number of cards, without going over. So... The user can choose whether to be hit with a new card (a number between 1 and 8) or fold and stop. Each number they are dealt adds up to their total . If the total goes over 21, then they lose . If they bust (when over 21) or folded then their final number and their number of cards is displayed . Blackjack 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: Think about the type of loop that you need. Will you need more than one loop? What variables will you need? Remember to use an input . What will you ask the user? How will you use their response? Remember to use ‘import random’ and randint to create a random number . What outputs do you need and when? What should you display… After each hand? At the beginning? At the end? ⬅ Extended Task 2 (Lottery) Extended Task 4 (Vet Surgery) ➡

Learn about ethical issues of IT including whistleblowing, discrimination, online safety and bias. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 5.1 - Ethical Issues Exam Board: OCR Specification: 2016 - Unit 1 What are ethics? Ethics refers to what is right and wrong . The following issues are often linked to or backed up by legislation. Whistle Blowing Definition: When a member of staff reveals that the organisation they work for are engaging in unlawful practices . This could include breaking privacy laws , threatening staff or environmental damage . In the UK , whistleblowers are protected by the Public Interest Disclosures Act (1988) . Under this law, whistleblowers are protected from being fired or being victimised (e.g. ignored for promotion ) as a result of their whistleblowing. Large organisations should consider establishing a whistleblowing policy that would outline how employees can raise concerns , who they should speak to and the support available to concerned staff. A famous whistleblower is Edward Snowden , who revealed in 2013 that many governments, including the USA and the UK, were spying on their civilians with widespread undocumented surveillance. Should Martin reveal that his company is dumping old computers into a lake or just stay quiet? Graham feels that, because of his disability, he is being ignored for a promotion that he deserves. Discrimination Definition: When an employee is treated unfairly because of a personal or physical characteristic over which they have no control . The Equality Act (2010) ensures equal treatment for all people irrespective of: race sexuality gender disability marital status (and many more) Examples of discrimination include offensive talk, harassment, unequal pay and being ignored for promotion. Use of Information Definition: Laws such as GDPR (General Data Protection Regulation ) and specifically the Data Protection Act (2018) ensure that organisations must responsibly process personal data. Organisations have a legal obligation to keep their employee and customer personal data secure and out of reach from unauthorised viewers. Considerations should be made about how the information is ethically collected , stored and processed . DataDyne backs up customer information on cloud storage - what if this data is compromised ? As part of quality assurance, Selside Bank double check performance reviews before submission. Codes of Practice Definition: A set of rules which explains how people working in certain professions are required to behave . Organisations may have a code of practice for: Confidentiality (rules on what data can and cannot be shared with others), Quality assurance (ensuring high quality is maintained for all products/services), Behaviour (setting out how employees are expected to behave at work and in communication with each other and customers), Equality and discrimination (being understanding and providing fair access to all employees). Employees must agree to the codes of practice so they are clear on their expectations of what is and isn't acceptable at work. The organisation can then discipline employees that broke the codes of practice they formerly agreed to. Online Safety Definition: Often companies will provide an induction (training ) to new employees about the organisation’s code of practice for using the internet whilst at work . If an individual does not behave safely online or breaks the organisation's codes of practice (by gambling at work for example) then they may be punished (e.g. fined or fired). Employees can ensure that they are safe online by using secure passwords that are regularly updated and preventing web browsers from remembering login details . Miriam changes her password each month to minimise the chance of hackers accessing her account. The CEO of Honey Media apologies in public after biased information led to a lawsuit and loss of reputation. Bias Definition: This is technically correct, but slanted , information that presents a one-sided view . For example, end-of year financial data that focuses on profits and ignores significant losses. Poor quality information may lead to an organisation being misinformed and not sufficiently responding to their customers' needs - for example if a survey was only completed by a small number of people it could generate biased results. As a result of poor quality information, organisations may suffer from damage to their reputation due to negative feedback and reviews from customers, possibly posted online. A lack of trust can occur if customers feel neglected because of decisions made using biased information of a poor quality, therefore reputational damage may lead to loss of customers . Q uesto's Q uestions 5.1 - Ethical Issues: 1. Describe what whistleblowing is and give 3 examples . [4 ] 2. Describe what discrimination is and give 4 examples . [5 ] 3. Which law relates to the use of information ? [1 ] 4a. Describe 2 things that may be included in an organisation's codes of practice . [4 ] 4b. Explain why employees must agree to their company's codes of practice [4 ]. 5. Describe 2 things an employee should do to stay safe online . [2 ] 6a. What is biased information ? [2 ] 6b. Describe 3 possible effects to a company if they use biased information . [6 ] 4.6 & 4.7 - Bodies & Certification Topic List 5.2 - Operational Issues

Learn how to use time commands to display the current date and time in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 5c - Time & Date ctime() The easiest way to output the current time and date is to use the ctime() command. Import the ctime command from the time library before you use and print it: from time import ctime print ( "Current time:" , ctime()) = Current time: Wed Sep 13 16:07:20 2023 This will print the time and date, but it looks rather unprofessional, and the exact format depends on the type of system that you are currently running so it may vary for different users. Date / Time Task 1 ( Dentist Surgery) Print a greeting for a dentist surgery with the current date and time. Example solution: Welcome to Greenvale Dentist Surgery, it is currently: Wed Sep 13 16:16:24 2023 strftime() A better alternative to the ctime() command is to use strftime() which stands for str ing f rom time as you can select specific parts of the date and time to display. This command requires a directive to be written with a percentage symbol as a string in the brackets . For example, the current hour (%H ), minute (%M ) and second (%S ) can be printed between colons to show the time . from time import strftime print ( "The current time is" , strftime( "%H:%M:%S" )) = The current time is 13:18:57 There are many different directives that you can use to display exactly what you are looking for, such as: from time import strftime day = strftime( "%A" ) print ( "The current day is" , day) month = strftime( "%B" ) print ( "The current month is" , month) year = strftime( "%Y" ) print ( "The current year is" , year) = The current day is Thursday The current month is September The current year is 2023 The following directives can be used with strftime(). Don't forget that directives must be typed within speech marks . Date - Weekday: %a – Current day of the week abbreviated (e.g. Sun, Mon) %A – Current day of the week in full (e.g. Sunday, Monday) %w – Current day of the week in chronological order (0 is Sunday and 6 is Saturday) %W – Current week number (e.g. 01, 26, 52) Month: %d – Current day of the month (e.g. 01, 11, 31) %m – Current month as a number (e.g. 01, 06, 12) %b – Current month abbreviated (e.g. Jan, Jun, Dec) %B – Current month in full (e.g. January, December) Year: %y – Current year abbreviated (e.g. 16, 17) %Y – Current year in full (e.g. 2016, 2017) %j – Current day of the year (e.g. 001, 150, 365) Time - Hour: %H – Current hour in 24-hour clock (e.g. 00, 12, 20) %I – Current hour in 12-hour clock (e.g. 01, 08, 12) %p – Whether it is currently AM or PM Minute: %M – Current minute (e.g. 00, 30, 59) Second: %S – Current second (e.g. 00, 30, 59) More Directives - %z – Current time difference from UTC (Co-ordinated Universal Time) (e.g. +0000, -0500, +1100) %Z – Current time zone (e.g. GMT Standard Time, EST, CST) Just looking for a quick date or time display and not bothered about customisation? Try these: %c – Current date and time in full (e.g. Tue Feb 19 13:35:20 2016) %x – Current date (e.g. 19/02/16) %X – Current time (13:36:20) Date / Time Task 2 ( Calendar App ) Create a program that asks the user if they want to see the current date , the current time or 'other '. Use the strfftime directives above to show what the user asks for. It's up to you which directives you use for the 'other' option , such as displaying the current day of the year (%j ) or current week of the year (%W ). Example solutions: Type TIME for the current time, DATE for the current date or OTHER: TIME The current time is 13:46PM Type TIME for the current time, DATE for the current date or OTHER: DATE The date today is Thursday 14 September 2023 Type TIME for the current time, DATE for the current date or OTHER: OTHER Did you know today is day number 257 of 2023? Between Dates You may want to work out the number of days between two dates . This can be done by importing the date command from the timedate library. Below is a simple example: from datetime import date date1 = date(2021,9,15) date2 = date(2022,1,20) difference = date2 - date1 print ( "There are" , difference.days , "days between" , date1 , "and" , date2) Make sure the date is entered in the format of year, month, day . The .days code removes the difference in hours and seconds to just display the number of days difference. There are 127 days between 2021-09-15 and 2022-01-20 Today's Date The program here uses strftime to check the current year, month and day and organise it into the date format . This can then be used together with code similar to the program above to check the number of days between one specific date and the current date. from datetime import date from time import strftime thisyear = int (strftime( "%Y" )) thismonth = int (strftime( "%m" )) thisday = int (strftime( "%d" )) todaysdate = date(thisyear,thismonth,thisday) print ( "The date today is" , todaysdate ) The date today is 2023-09-14 Input a Date The program here shows how to input a date into a format that can then be used by Python to work out the difference between two dates . from datetime import date year = int ( input ( "Enter a year: " ) month = int ( input ( "Enter a month: " ) day = int ( input ( "Enter a day: " ) chosendate = date(year,month,day) print ( "The chosen date is" , chosendate ) Enter a year: 1964 Enter a month: 5 Enter a day: 13 The chosen date is 1964-05-13 Date / Time Task 3 ( Days Alive) Create a program that works out how long the user has been alive for . Use the examples above to automatically make today's date and then allow the user to input their year , month and day of birth. Get Python to work out the difference between today and their date of birth. Example solutions: Enter a year: 1998 Enter a month: 3 Enter a day: 29 You have been alive for 9300 days! Enter a year: 2007 Enter a month: 12 Enter a day: 25 You have been alive for 5742 days! ⬅ 5b - Sleep 5d - Colorama ➡

Learn how to create and use functions in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 7b - Functions What is a Function? A function is a subroutine that takes one or more values from the main program and returns a value back. For example, transferring over a sphere’s radius from the main program for the function to calculate a surface area and then return that value to the main program. The two key differences between procedures and functions are: A function uses parameters to transfer data from the main program into the function. A function returns a value to the main program. Writing Functions A function is written the same way as a procedure but it uses parameters . In the example below the parameters are num1 and num2 which are sent from the main program to be used in the function . The return command is used to send a value back to the main program . Below is another example of a function that takes the radius of a sphere and works out the area in a separate function . The area is returned to the main program and printed. Subroutines can be reused and called with different parameters . The program below repeatedly takes an integer input and adds it to a total in a function that is then returned and printed. Practice Task Create a program similar to the sphere example above, this time to work out the volume of a cylinder. In the main program ask the user to enter the cylinder's radius and then its height. The actual calculation should be done in a function and returned to the main program. The calculation for a cylinder's volume is: pi x (radius x radius) x height Extension: Use the round command from section 9b to round the number to 2 decimal places. Example solution: Using Subroutines as a Menu Subroutines are often used to split programs up and give users a selection of options . Subroutines are used for this purpose because they are separate , making it easier to code and manage a program . The example below for a simplified online banking system uses separate subroutines accessible within a while true loop . Depending on the option chosen by the user, the appropriate subroutine will be called . Instead of a further practice task here, Task 4 of the Section 7 Practice tasks page challenges you to make a similar program using multiple subroutines. ⬅ 7a - Proced ures Section 7 Practice Tasks ➡

Learn about different types of hardware that allow data to be sent between systems, including router, modem, bridge and WAP. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.5: Communication Hardware Exam Board: OCR Specification: 2016 - Unit 1 The devices on this page are used to create or link together networks , allowing data to be sent between computer systems . Hub A hub receives data packets from a connected device and transfers a copy to all connected nodes . Switch A switch receives data packets , processes them and transfers them on to the device s pecifically listed in the destination address of the packet. Modem Modems are used to send data across the telephone network . The telephone lines can only transfer analog signals so a modem is used to convert a computer's digital data into an analog signal . Another modem converts the signal back to a digital format at the receiving end. Router Routers are used to transfer data packets between networks . Data is sent from network to network on the internet towards the destination address listed in the data packet. A router stores the address of each computer on the network and uses routing tables to calculate the quickest and shortest path . Wireless Access Point (WAP) Provides a link between wireless and wired networks . It creates a wireless local area network that allows WiFi enabled devices to connect to a wired network. Combined Device Also known as a hybrid device , this provides the functionality of multiple communication devices (e.g modem, router, switch and/or wireless access point) in a single device . They can be more expensive than a single device but are more adaptable - if the routing part of the device fails it might still be able to function as a switch / wireless access point etc. However, you will see an increased performance from a standalone device rather than a combined one as standalone devices have more complex features (e.g. VPN support). Network Interface Card (Network Adapter) A Network Interface Card (often shorted to NIC ) is an internal piece of hardware that is required for the computer to connect to a network . It used to be a separate expansion card but now it is commonly built directly into the motherboard (and known as a network adapter ). Wireless network interface cards allow wireless network connection. Q uesto's Q uestions 1.5 - Communication Hardware: 1. What is the difference between a hub and a switch ? [2 ] 2. Explain how a modem works. [3 ] 3. Explain the purpose of a router . [2 ] 4. What is a Wireless Access Point (WAP )? [2 ] 5. Describe what is meant by a 'combined device '. Give one advantage and one disadvantage of using a combined device. [3 ] 1.4 - Connectivity 1.6 - Hardware Troubleshooting Topic List

Test your understanding of data structures such as lists (one-dimensional and two-dimensional) and dictionaries. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 8 Practice Tasks Task One Write a program with a blank list. Use the .append() command to add your three favourite ice-cream flavours to this list and then print the list. Example solution: Task Two Write a program with a list of any 5 numbers. Print the list. Delete the first and third numbers. Print the list. Example solution: Task Three Write a program with a list of three different animals. Write an input line that lets the user type an animal. Add what the user has written to the list and print the list. Example solution: Task Four Sort your list from task two into order. Then print the list. Example solution: Task Five Copy the text on the right and put it into a list named countries. Count the number of countries in the list. Print the longest country. Use a for loop to work out the length of each country. "Egypt", "Angola", " Eritrea " , "Mozambique" , "Ghana" , "Chad" , "Somalia" , "Namibia" , "Sudan" , "Libya" , "Algeria", "Morocco" , "Cameroon" Example solution: Task Six Create a dictionary (see 8c ) that asks users questions about yourself, such as first name, favourite colour or birthday. Let the user answer each question and display the answer if they get it correct. Use the 'Using a Dictionary to Make a Game ' section of 8c to help you. Example solution: ⬅ 8c - Dictionar ies 9a - String Handling ➡

Learn about the moral and ethical issues of computing such as computers in the workforce, automated decision making, artificial intelligence, environmental effects, censorship and the internet, monitor behaviour, analysing personal information, piracy and offensive communications, layout, colour paradigms and character sets. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 5.2 - Moral & Ethical Issues Watch on YouTube : Moral & Ethical Issues #1 Moral & Ethical Issues #2 Artifical Intelligence Technology and the internet have transformed society , bringing huge benefits but also raising new ethical , social and environmental challenges . Below are some key modern issues linked to computing and digital systems . Moral & Ethical Issues Computers in the Workforce: Computers and automation have increased productivity and created new tech-based jobs , but they have also led to job losses in areas where machines can replace human labour . This raises concerns about unemployment and retraining in many industries . Automated Decision Making: Systems such as credit checks and recruitment tools now make decisions automatically using algorithms . While this can save time and reduce human bias , it can also lead to unfair or inaccurate outcomes if the data or programming is flawed . Artificial Intelligence (AI): AI allows machines to learn and make decisions without explicit human control , improving fields like healthcare and transport . However, it also raises ethical questions about accountability , job loss and the potential misuse of intelligent systems . Environmental Effects: Computers require energy to manufacture , use and dispose of , contributing to electronic waste and carbon emissions . Recycling and energy-efficient design can help reduce the environmental impact of modern technology . Censorship and the Internet: Some governments and organisations restrict access to information online to control what people can see or share . While this can protect users from harmful content , it can also limit freedom of expression and access to knowledge . Monitoring Behaviour: Digital systems and surveillance tools can track users’ actions , such as browsing history or location . This can improve safety and security but also raises privacy concerns about who collects this data and how it’s used . Analysing Personal Information: Companies and governments can collect and analyse large amounts of personal data to improve services or target advertising . However, this creates risks of data misuse , discrimination or identity theft if information isn’t protected properly. Piracy and Offensive Communications: The internet makes it easy to copy and share content illegally , such as music , films or software , leading to lost income for creators . It can also be a platform for offensive or harmful communication , such as trolling or cyberbullying , which can have serious social effects . Layout, Colour Paradigms, and Character Sets: Design choices like layout , colour schemes and character sets affect how accessible and inclusive digital content is. Using clear design , appropriate colours and Unicode character sets helps ensure that websites and software can be used by people of all languages and abilities . YouTube video uploading soon YouTube video uploading soon YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Moral & Ethical Issues: moral, social, ethical, cultural, opportunities, risks, computers in the workforce, automated decision making, artificial intelligence (AI), environmental effects, censorship, the internet, monitor behaviour, analysing personal information, piracy, offensive communications, layout, colour paradigms, character sets D id Y ou K now? In 2022 , the world generated 62 million tonnes of e-waste (roughly 7.8 kg per person globally) and only 22% of it was formally collected and recycled . 5.1 - Computing Legislation A-Level Topics