Lesson Notes By Weeks and Term v5 - Grade 8

Lesson Video

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Performance objectives

• Define the elements of a communication system
• Explain different forms of graphic communication
• Apply basic principles to create visual messages
• Evaluate the effectiveness of communication systems
• Sketch simple objects using freehand techniques

Lesson summary

This week, we delve into the fascinating world of communication systems and graphic communication. Communication is the backbone of any society, enabling us to share information, ideas, and emotions. Graphic communication, specifically, focuses on conveying messages visually, through images, symbols, and designs. Understanding communication systems and graphic communication is crucial because it equips you with the skills to effectively communicate your ideas, interpret messages from others, and participate meaningfully in our increasingly interconnected world. From understanding the local news on television to designing a poster for a school event, these skills are invaluable.

Lesson notes

2.1 Elements of a Communication System: Every communication system, whether simple or complex, consists of the following core elements: Source/Sender: The originator of the message. This could be a person, a computer, or any device that generates information.

Example:* A newsreader on T

V. Encoder: The device or process that converts the message into a signal suitable for transmission.

Example:* A microphone converting the newsreader’s voice into an electrical signal. Or a keyboard changing text to binary for a computer.

Channel: The medium through which the signal travels from the sender to the receiver.

Examples:* Airwaves (for radio), cables (for TV), the internet (for email), a piece of paper (for a hand-written letter).

Decoder: The device or process that converts the received signal back into a form that can be understood by the receiver.

Example:* A TV set converting the electrical signal back into sound and images. Or a computer using software to convert binary code back to readable text on the screen.

Receiver: The destination of the message.

Example:* You, watching the news on TV, or reading an email.

Feedback: The response from the receiver to the sender, indicating whether the message was received and understood.

Example:* A viewer agreeing or disagreeing with a news report, expressed through social media. Or replying to an email.

Noise: Any interference that disrupts the transmission of the signal.

Example:* Static on the radio, a poor internet connection, or illegible handwriting. 2.2 Forms of Graphic Communication: Graphic communication is the process of conveying ideas and information through visual means.

Key forms include: Sketching: Quick, freehand drawings used to explore ideas and communicate them rapidly. Sketching emphasizes capturing the essence of an object or concept. Think of a designer sketching initial ideas for a new sneaker or a builder quickly sketching the outline of a house. Sketching does not require tools but can be done with any pencil and paper.

Technical Drawing: Precise and accurate drawings used to represent objects according to specific conventions and standards. Technical drawings are used in engineering, architecture, and manufacturing to provide detailed instructions for construction and fabrication. They use specific tools like rulers, compasses, and protractors.

Example:* A blueprint for a building, showing dimensions, materials, and construction details.

Computer-Aided Design (CAD): Using computer software to create and modify technical drawings and 3D models. CAD offers advantages such as accuracy, efficiency, and the ability to easily share and modify designs.

Example:* Designing a new car part using software like AutoCAD or SolidWorks.

Diagrams and Charts: Visual representations of data and processes, used to simplify complex information and make it easier to understand.

Examples:* Bar graphs, pie charts, flowcharts, maps.

Photography and Videography: Capturing images and videos to document events, convey information, and create visual narratives.

Examples:* A photograph in a newspaper, a documentary film, or a social media video. 2.3 Principles of Effective Graphic Communication: Clarity: The message should be easy to understand and free from ambiguity. Use simple language, clear visuals, and logical organization. Avoid jargon or technical terms that your audience may not understand.

Simplicity: Avoid unnecessary details and complexity. Focus on conveying the essential information in the most concise and straightforward way possible.

Visual Appeal: Use design elements such as color, typography, and layout to make the message visually engaging and attractive.

However, visual appeal shouldn't compromise clarity. A poster using too many fonts may be aesthetically pleasing but hard to read.

Accuracy: Ensure that all information presented is accurate and up-to-date. This is especially important in technical drawings and diagrams.

Consistency: Maintain a consistent style and format throughout the communication. This helps to create a professional and cohesive look. 2.4 Analog vs.

Digital Communication Systems: Analog Communication: Transmits information using continuous signals that vary in amplitude, frequency, or phase.

Example:* Traditional radio broadcasts, where the audio signal is transmitted as a continuous radio wave. Older landline telephones are also analog.

Digital Communication: Transmits information using discrete signals represented by binary digits (0s and 1s).

Example:* Internet communication, where data is transmitted as packets of digital information. Mobile phones, computers, and digital television use digital communication.

Key Differences: Signal Type: Analog uses continuous waves; Digital uses discrete values (0s and 1s).

Noise Sensitivity: Analog is more susceptible to noise and distortion; Digital is more robust.