Qualification:
Cambridge Advanced Nationals in Computing (AAQ)
Certificate:
Computing: Application Development (H029 / H129)
Unit:
F161: Developing Application Software
2.2 - Data Flow
Watch on YouTube:
Data vs Information
Data Input
Information Output
Black Box Concept
You need to know the difference between the terms 'data' and 'information' and how data is input to be converted to information as an output. There are specific types of input and output, including numbers, text, movement, audio and images.
You need to understand how data and information flows through application software and can be stored. You must be able to represent data flow in a diagram using the black box concept.
What You Need to Know
Data and Information
Data is raw, unprocessed facts and values, while information is data that has been processed and given meaning or context so that it is useful.
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Data is converted into information through processing, such as calculating, sorting, filtering, comparing or organising it. For example, individual test scores are data and then calculating the class average produces information.
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Data flows into an application through inputs, is processed and/or stored and then flows out as useful information through outputs.
Data
Processed to give meaning
Information
Data Input & Information Output
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Numbers are numerical data entered into or produced by a system, including a whole number (integer) and decimal values (real). For example, entering a person's age, recording a temperature from a sensor or displaying a player's score.
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Text includes letters, numbers, symbols or words entered into or displayed by a system. For example, entering a username, typing a search query, displaying instructions or showing an error message.
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Movement is data about the position, direction or motion of a person or object, often captured using sensors or cameras. Examples include a phone detecting that it has been tilted, a fitness tracker detecting steps or a games console detecting controller movements.
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Audio is sound that is captured as input or produced as output by a system. Examples are speaking into a microphone for voice recognition, recording music, playing sound effects or receiving spoken directions from a navigation app.
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Moving images are a sequence of images displayed rapidly to create the appearance of movement, usually as video or animation. For example, recording video with a camera, watching a video tutorial, a video call or an animation in a game.
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Static images are single images that do not move, such as a photograph, drawing or diagram. Examples are taking a photo with a phone camera, scanning a QR code, displaying a logo or showing an image in an app.
Storage Locations
Black Box Concept
The black box concept is a way of representing a system by focusing on what data enters the system, what is stored and what information leaves the system, without needing to understand the internal processes or any code.
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For example, consider a school quiz application:
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Flow-in is data that is entered into the system from an external source. Such as when a student selects an answer to a multiple-choice question, which is sent into the quiz application.
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Flow to storage is data that the system saves so that it can be accessed later. For example, the student's answer and score are saved to a database so their results can be viewed later.
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Flow-out is information that is sent out of the system to a user or another system, such as the quiz application displaying the student's final score on the screen.
Flow In
product choices & payment details
Flow to Storage
customer's order & account details
Flow Out
order confirmation & receipt
Online Shopping System
Storage
See section 1.3 for information about the two main storage locations required for application software: on-site storage and cloud storage.
Questo's Questions
2.2 - Data Flow:
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1. Explain the difference between data and information, giving an example of each. [3]
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2. Explain how application software can process data to turn it into useful information. ​[2]
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3. Describe the following types of input/output data and give an example of each: number, text, movement, audio, moving images and static images.​ [2 each]
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4. Explain the black box concept and the terms flow in, flow to storage and flow out. [4]
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5. Using an application of your choice, describe how data could flow into the application, be processed or stored, and flow out as useful information. [4]
A controller isn't the only way to play a video game! The Nintendo Wii and Nintendo Switch can use movement as input, music games like SingStar use audio from microphones, and the EyeToy on the PlayStation 2 used images from a connected camera.
Did You Know?
