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1.1 Data, information and knowledge

1.1 information

1.2 Sources of Data

1.3 Quality_of_information

1.4 Impact of Information Technology

1.5 Checking the accuracy of data

2.1 Hardware and software

2.2 System, application and user interface software

3 Monitoring and control

   
   
   
   
   
   
   
   
   
   

 

   
   
 

Data Flow Diagram

A data flow diagram (DFD) illustrates how data is processed by a system in terms of inputs and outputs. As its name indicates its focus is on the flow of information, where data comes from, where it goes and how it gets stored.

data flow diagram (DFD) is a graphical representation of the "flow" of data through an information system, modelling its processaspects. A DFD is often used as a preliminary step to create an overview of the system without going into great detail, which can later be elaborated.[2] DFDs can also be used for the visualization of data processing

What is Level 0?
Level 0 is a web based software tool that districts use to ensure that the data they transfer to the data warehouse is in the correct format and that the required fields are complete. The tool can be accessed from anywhere there is an internet connection.
What is meant by level 1 DFD?
The Level 1 DFD shows how the system is divided into sub-systems (processes), each of which deals with one or more of the data flows to or from an external agent, and which together provide all of the functionality of the system as a whole.

 

What is the difference between Level 0 and Level 1 DFD?
Context Diagram. A context diagram is a top level (also known as "Level 0") data flow diagram. It only contains one process node ("Process 0") that generalizes the function of the entire system in relationship to external entities. DFD Layers.

 

Different levels of Data Flow Diagram DFD

The data flow diagram levels are numbered 0, 1 or 2, and this may go to the Level 3 or beyond.

One think to notice that the level of detail depends upon the scope of what we are trying to represent.

 

 

They are the different levels of DFD we will talk about:

0 level DFD

  • Sometimes, it is called as a Context Diagram.
  • It visualizes the glance as if you are looking into a system through a helicopter.
  • It’s a basic overview of the whole system.
  • It shows the system as a single high-level process, along with its relationship to the external entities.
  • Easily understood by a Layman.

Here is the example of o level DFD

1 level DFD

  • It provides a more detailed view of the Context Level Diagram.
  • Here, the main functions carried out by the system are highlighted as we break into its sub-processes.

Here is the example of 1 level DFD

2 level DFD

  • Level 2 DFD goes one step deeper into parts of Level 1 DFD.
  • This level of DFD may require more text to reach the necessary level of detail about the functioning of the system.

 

 

 

 

 

BarCodes and QR Codes

While a barcode only holds information in the horizontal direction, a QR code does hold information in both horizontal and vertical directions. Due to this, a QR code holds hundreds of times more information than a barcode.

I went to a grocery store a few days ago with a friend. At the billing counter, as is routine, the salesman flashed a hand-held device at a particular spot on the packaging of the product, and just as the device ‘beeped’, he picked another product and repeated the same procedure.

‘You see those black parallel lines? Those form a barcode.’ my friend informed me.

‘Yeah, I know. But do you know what do they do?’ I enquired, to which, the following expression flashed on his countenance:

We come across barcodes almost every time we buy something from a store. But what do they actually do? And how are they different from the increasingly popular QR codes?

What is a Barcode?

Anyone who buys stuff from stores must have seen barcodes; however, whether or not they realize it’s a barcode they are looking at is a different matter altogether! A barcode is a visual representation of machine-readable information about the product to which it’s attached. To put it down for a layman, a barcode is that small box printed on the packaging of a product, that has a small collection of black parallel lines of varying widths.

This isn’t just another box printed atop the cover of the product, it contains important information like the manufacturer’s name, type of item, price and so on, which can only be read by dedicated barcode reader machines. Since it only consists of data stored in horizontal direction, it is also dubbed as linear or 1D (1-dimensional).

What is a QR code?

 


 

 

Quick Response code, often abbreviated as QR code, is much similar to a barcode. In fact, it’s a type of barcode. Like barcode, it also contains machine-readable information concerning the item to which it is attached. But, unlike a regular barcode, a QR code is two-dimensional, i.e. it contains information both in vertical and horizontal directions.

QR codes contain a lot of information within them. From giant corporate organisations to next-door grocery store, everyone can create their own QR code and attach them to their products. This, for example, is the QR code of the URL of our website:

nformation-holding capacity

This also concerns the design of the two codes. While a barcode only holds information in the horizontal direction, a QR code does hold information in both horizontal and vertical directions (hence the name ‘2-Dimensional code’). Owing to this structural difference, a QR code holds hundreds of times more information than a barcode, and has a greater potential to hold more information in a smaller space than a barcode.

Possible QR Code Applications

Now, let’s look at some business-related scenarios where you would use QR codes.

  • Use a QR Code to direct a customer to the URL for your website, Facebook, Twitter or other social media page.
  • Use it to share a text message (anything from “Happy Holidays!” to “Have you seen what we have upstairs?)
  • Use it as a discount code to be taken to the checkout counter for 10 percent off, for example.
  • Use it on your business card with your contact details embedded inside the code.
  • Use it to link to a Google Maps location for your new store location perhaps.
  • Use it to link to a YouTube video or channel perhaps demonstrating new products or funny company videos.
  • Use it to link to an app store download (perhaps of your company’s latest eCommerce app?)
  • Use it to embed pricing for your products as an alternative for more conventional price tags.
  • Put it on your website’s “contact us” page allowing people scan it and get your contact information direct on their phones.
  • Put the code on the tables and walls of your restaurant as an easy way for customers to send off a Foursquare or Facebook status update.
  • Put a code on your restaurant’s takeout menu allowing customers to scan it with their phones and instantly call to place an order.
  • Put a QR code at the end of promotional videos taking viewers to a landing page on your website.

 

 

   
   
   
   
   
   
   
   
   

 

 

P1 Practice Questions

 

1. Data, information, knowledge and processing

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Candidates should be able to:

1..1   Data, information and knowledge

  • define data, clearly identifying that data has no meaning
  • define information and show how data can become information through context and meaning
  • define knowledge and understand that information becomes knowledge when human experience is applied
Sample Rate and Bit Rate
 

LOSSLESS COMPRESSION

 

1.2   Sources of data-------------[Download]

  • define static data and give an example
  • define dynamic data and give an example
  • compare the use of static information sources with dynamic information sources
  • define direct and indirect data source
  • understand the advantages and disadvantages of gathering data from direct and indirect data sources

1.3        Quality of information

  • understand how accuracy, relevance, age, level of detail and completeness of the information can affect

its quality

1.4          Coding, encoding and encrypting data [Download]

  • describe the coding of data (including: M for male, F for female) and more intricate codes (including:

clothing type, sizes and colour of garment)

  • discuss the advantages and disadvantages of the coding of data
  • evaluate the need for encoding data and analyse the different methods that can be used to encode data

(including. codecs)

  • define encryption and describe different methods of encryption (including: symmetric, asymmetric,

public key, private key)

  • evaluate the need for encryption and how it can be used to protect data such as on a hard disk, email or

in HTTPS websites

  • discuss encryption protocols (including: the purpose of Secure Socket Layer (SSL)/Transport Layer

Security (TLS) and the use of SSUTLS in client server communication)

1.5         Checking the accuracy of data--------[Download]

  • define validation and analyse a range of validation methods (including: presence check, range check,

type check, length check, format check and check digit, lookup check, consistency check, limit check)

    • define verification and analyse verification methods (including: visual checking and double data entry)
    • explain the need for both validation and verification
    • define proof reading
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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