Topic outline

  • General

    An Introduction to Computer Science 

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  • Topic 1

    Data - The Basics

    Objectives

    Students should understand how computers represent data:


    Intro to binary manipulation.


    Representations of:

    o Text.  [Key point: each character is represented by a bit pattern.  Meaning is by convention only. Examples: Morse code, ASCII.]

    o Sounds [involving analogue to digi conversion, e.g. WAV, & free of such conversion, e.g. MIDI]

    o Pictures [e.g. bitmap] and video.

     

    Many different things may share the same representation, or the meaning of a bit pattern is in the eye of the beholder” *e.g. the same bits could be interpreted as a BMP file or a spreadsheet file; an 8-bit value could be interpreted as a character or as anumber].

     

    The things that we perceive in thhuman world are not the same as what computers manipulate, and translation in both directions is required [e.g. how sound waves are converted into an MP3 file, and vice versa]


    There are many different ways of representing a single thing in a computer. [For example, a song could be represented as:

    A scanned image of themusical score, held as pixels

    o A MIDI file of the notes

    o A WAV or MP3 file of a performance]

     Different  representations  suit  different  purposes  [e.g.  searching,  editing,  size, fidelity].

    Starter

    Look at the What are these? presentation (see bottom of section) and discuss with a partner an answer to the question. 
    Once you have an answer to that question then what is the image below?
    numbers

    Task 1

    You will be talked through a basic explanation of binary (see bottom of section)
    Ask questions and make notes to ensure you understand what binary is and how to write/read a binary number

    Task 2

    Watch this:

    Ask for help if you are still unsure about binary numbers and how to represent them as decimal numbers. 

    When you are ready, attempt the binary manipulation question (see bottom of section)


    Homework

    Attempt the ASCII questions homework (see bottom of section)


    Plenary

    You may have seen adverts like these:
    What do they mean?

    The speed of a computer depends on the number of bits it can process at once. For example, a 32-bit computer can process 32-bit numbers in one operation, while a 16-bit computer must break 32-bit numbers down into smaller pieces, making it slower.
     
    Ultimately bits and bytes are all that a computer uses to store and transmit numbers, text, and all other information. In some of the later activities we will see how other kinds of information can be represented on a computer.

    (courtesy of csunplugged.org)

  • Topic 2

    Data - Representations

    Starter

    ASCII recap to ensure students understand and recall what ASCII is using http://www.webopedia.com/TERM/A/ASCII.html

    Task 1

    http://www.wordsmuggler.com/ 

    1. Have a quick play with this site using both ASCII and Binary smugglers
    2. Choose a partner
    3. One of you set a Binary message that your partner must decipher before pressing the Decipher button 
    4. The other partner set an ASCII message that you must decipher before pressing the Decipher button
    5. You can both use the internet for resources and assistance on how to calculate binary and ASCII tables


    Task 2

    In 2 teams, where one team are the MIDIs and the other are the ADCs you have to come up with a short rap in your own words. The explanation for each team is given below:
    MIDIsUse http://entertainment.howstuffworks.com/midi1.htm
    Explain what MIDI is and how it works.
    The rap should relate to computer data
    ADCsUse http://electronics.howstuffworks.com/analog-digital3.htm
    Explain what analogue to digital conversion and how it converts into computer data

    When the raps are delivered by the opposing team, ensure you are taking notes so you understand what both analogue to digital conversion and MIDI are and the difference between them

    Task 3

    Your teacher will give you a short presentation on how video data is represented by computers. You should take notes and ask questions to ensure you understand this

    Plenary

    Click on http://www.philtulga.com/morse.html#Activities and create Morse Code Music for your name. This should show you how data can be represented in many different formats

    • Topic 3

      Computers

      Objectives

      Students should know the main components that make up a computer system, and how they fit together (their architecture). 

      Computers are devices for executing programs

      Computers are general-purpose devices

      Not  every  computer  is  obviously  a  compute

      Basic architecture: CPU, storage input/output

      Computers are very fast, and getting faster all the time (Moore’slaw)

      Computers can pretend to do more than one thing at a time

      Starter

      Watch this video and make 2 lists of:

      1. all computerised devices that you see
      2. all the different things done using technology

      Points to note:

      • Computers are general-purpose devices. They can be made for many different purposes and to perform many different functions
      • Not all computers look like computers but many electronic devices are computer controlled. 

      Defintion: Computers are devices for executing programs


      Task 1 - Understanding hardware components

      I/O Devices

      1. Complete the 'What are these?' exercise. (See file at bottom of section)
      2. Which of the devices shown are input and which are output devices?

      Storage & Processing

      Watch http://www.commoncraft.com/video/computer-hardware and be able to answer the questions:

      1. What is a CPU?
      2. What is storage?


      Task 2 - Computers are getting faster and faster

      Using resources on  http://www.scoop.it/t/computer-hardware answer the question, What is Moore's Law?


      Homework

      Scenario: Jade-Marie is about to go to College in America (university) because she has won a scholarship to play soccer (football) for their team. She will major in (study) Sports Psychology for the academic side of things.

      Her parents are going to fly out with her when she goes later in the year and on this trip plan to buy her a laptop she can use while at the college. As this will be in a different country, other than the likelihood of the price being lower than in the UK, they do not know what will be on offer. They are quite inexperienced in buying computers and are worried that they will become a target for a knowledgable, crafty salesman. They have emailed you for advice saying that they want all sorts of things from the laptop but they definitely want it to be fast and be able to store videos and images as well as help Jade-Marie with all her work. They want to understand what things to look out for that effect how fast the laptop is and the amount of/how things can be stored.

      Task: Using the http://www.scoop.it/t/computer-hardware materials, prepare an email explaining the main hardware components of a laptop that they need to know about which affect speed and storage. Make sure it is in plain English that they can understand and not just copied and pasted from websites they have already read.  Include in your email, an explanation of how computers can seem to do more than one thing at a time and what will affect the speed at which they do this.

    • Topic 4

      Communication & the Internet

      Objectives

      Students should understand the principles underlying how data is transported on the Internet.

      network is a collection of computers working together

      An end-to-end understanding of what happens when a user requests a web page in a browser, including:

      o Browser and server exchange messages over the network

      o What is in the messages[http request, and HTML]

      o The structure of a web page - HTML, style sheets, hyperlinking to resources

      o What the server does [fetch the file and send it back]

      o What the browser does [interpret the file, fetch others, and display the lot


      How data is transported on the Internet:

      o Packets and packet switching

      o Simple  protocols: an  agreed language for two computers to talk to each other. 

      How search engines work & how to search effectively

      Starter

      Look at the netactivity image (see bottom of section).

      Question: How long should the stopwatch show in the middle for activity on the internet?

      Task 1

      Watch this video and answer this question:

      1. What role do messages play when being sent between a browser and internet servers?

      Points to note:

      The internet is a vast computer network linking smaller computer networks worldwide (dictionary.reference.com)

      Networks are collections of computers working together


      Task 2

      Group competition time!! Here's what will happen-

      • Your teacher will split the class with a few Browser groups on one side and a few Data groups on the other. 
      • Both sides of the class will have to prepare small presentations within the groups (so each group has their own presentation)
      • All work in the presentation has to be original i.e. no copying and pasting or just re-typing exactly what you have read or seen
      • Every member of each group has to understand what is in the presentation, be able to answer questions on it, explain it, present it 
      • When these presentation are complete they will be shown to one of the groups from the other side who will take notes from the information given so make sure they are understandable for your fellow students
      • Resources that the groups can use for their presentations are given below:

      Browser



      Data

    • Topic 5

      Algorithms - The basics

      Objectives

      A pupil should understand what an algorithm is, and what algorithms can be used for. 

      An algorithm is a sequence of precise steps to solve a given problem

      Asingle problem may be solved byseveral different algorithms.

      The choice of an algorithm to solve a problem is driven by what is required of the solution [such as code complexity, speed, amount of memory used, amount of data, the data source and the outputs required].


      The need for accuracy of both algorithm and data [difficulty of data verification;

      garbage in, garbage out

      Starter

      Watch this short animation. Work with a partner and list everything you see. What do the things you see have in common?

       

      Task 1

      What is an algorithm?

      These are possible answers to the question. Read through the descriptions below and discuss with a partner what you like/don’t like, understand/don’t understand. Ask your teacher questions for anything you don’t understand then come up with a definition to answer the question in your own words with your partner.

      Description 1

      An “algorithm” is a set of instructions for completing a task. The idea of an algorithm is central to computer science. Algorithms are how we get computers to solve problems. Some algorithms are faster than others, and many of the algorithms that have been discovered have made it possible to solve problems that previously took an infeasible length of time (http://www.ncwit.org/pdf/ComputerScience-in-a-Box.pdf)

      Description 2

      Algorithms are rules or procedures for solving problems.  In the context of computers, two important aspects of algorithms are that the problem has to be completely defined, and the steps of the procedure have to be specified with absolutely no ambiguity. (http://csta.acm.org/Curriculum/sub/CurrFiles/L1-Objectives-and-Outlines.pdf)

      Description 3

      an algorithm can be represented as a sequence of instructions to be carried out until an end point is reached; algorithms are the rules, conditions or sequence by which the computer or people tackle a problem or situation. (http://www.computingatschool.org.uk/data/uploads/CPinKS3.pdf/)


      Task 2

      Algorithms can be represented with diagrams, instructions or a combination of both. Again working with your partner, you are to attempt to come up with a flowchart and step-by-step instructions of how to play noughts and crosses. Work together with one of you creating the flowchart and the other the instructions. Use the symbols below for the flowchart:
       
      symbols

      Task 3

      Play through the tutorials on http://www.robozzle.com/

      • Topic 6

        Algorithms - The choice and accuracy

        Starter

        Play a game of Battleships against the computer using http://www.learn4good.com/games/board/battleship.htm. As you are playing be prepared to answer the question of what algorithm would you give to someone who has never played this game before to help them how to play the game?


        Task 1

        Your teacher will give you a demonstration of Robomind and how a simple script is written which controls a robot to paint on the floor. This script is a set of instructions, i.e. an algorithm

        Now it is your turn:

        1. Examine the script carefully and the commands it uses to paint the letters
        2. Start a new Robomind file and write a script that paints your initials on the floor (e.g. if your name is John Snow, paint JS)

        Task 2

        Creating algorithms is not a perfect science. One chosen solution (algorithm) may be different from another and some more efficient than others

        So, now we are going to see if people choose a different way to solve a problem in Robomind:

        1. Open the findspot1 map in Robomind (see screenshot1 below of where to find that)
        2. Write a script that finds the spot (shown in screenshot2 below). This script should have the robot searching for the spot i.e. it doesn't know already where the spot is 
        3. When you think you have done it, have a look at other peoples and compare what you have done with theirs

        screenshot1

        screenshot1

        screenshot2

        screenshot2


        Plenary

        Look at the efficiency of various solutions to this problem.

        What do you think about how many steps the robot has to follow to get to the spot?

        Could your solution have been improved?



        • Topic 7

          Programming

          You are going to be using http://www.codeavengers.com to learn some javascript programming.CodeAvengersCA

          Code Avengers is a free interactive online tutorial that will teach you Javascript, the computer programming language of the web

          1. Click Start Training 
          2. Log in using your school email address and choose a password
          3. Read instructions carefully and take in as much information as possible
          4. Start coding!!
          Please note: You are expected to complete at least 2 lessons (10 tasks as there are 5 tasks in each lesson) in each period of ICT

        • Topic 9

          • Topic 10

            • Topic 11

              • Topic 12