M150: Data, Computing and information

Outline

1.Unit two.

2.What’s next.

3.Some questions.

4.Your questions.

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1- Unit two : Representation

Communication, convention and representation.

Properties of representations.

Picking representations.

Sharing and formats.

Computer based activity: a case study.

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1- Unit two : communication

Communication satisfies the following requirements:

Need for human beings to interact with each other.

A means for sharing information.

Sophistication that sets us apart from animals.

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1- Unit two : communicationCommunication also governs the human/machine and machine/machine relationship:

Extending the human/human communication.Internet connectivity.Chatting.Emails.

Using computers to solve problems or perform tasks either individually or collectively.

Word Processing.Speech Synthesis.Iris scanning.Interferometry.Etc…

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1- Unit two : communication

Communication between two (or more) parties requires a common ground, an agreement that all can follow and understand.

Such an agreement would be known as a convention or a protocol.

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1- Unit two : convention

The main convention for human/human communication is the language.

Some protocols for communication with computers:

HTTP (Hyper Text Transfer Protocol) for web pages addresses.FTP (File Transfer Protocol) for downloading files from the Internet.SMTP (Simple Mail Transfer Protocol) for sending and receiving emails.

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1- Unit two : convention

A convention is all about representation which is a combination between a form (symbol, image, sound, etc…) and a content.

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1- Unit two : Representation

Properties of representations:The form of the representation must be perceivable in a way.

The communicating parties understand the relationship between the form and the content.

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1- Unit two : Representation

Examples of representations:Auditory perceived as sound (ex: spoken language).

Visual perceived as sight (ex: flags, traffic signs, etc…).

Tactile perceived by touch (ex: Braille alphabet).

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1- Unit two : Picking Representation

The relationship between form and content is not predefined, it is a consensus between the communicating parties.

The following form would mean “V” in English as it would also mean 5 in Roman numbers (context sensitivity).

A key element for a representation is precision (ex: clock accuracy in the representation of time).

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1- Unit two : Picking Representation

The choice of a representation is crucial for achieving a certain task.

The fit-for-purpose criteria is essential, a representation must include sufficient information while stripping out irrelevant detail.

The process of minimizing information for a fit-for-purpose representation is called abstraction.

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1- Unit two : Representation characteristics

Very few representations are independent, most of them belong to complex representation systems which have two characteristics:

The form of a representation is made out of basic parts.

The meaning of the representation is constructed from the meanings of its basic parts.

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1- Unit two : Representation

Examples of complex representation systems are a game of cards and the traffic signs system.For the cards:

The basic parts are the card numbers, colors, and symbols.The meaning or value of a card in a game depends on the features mentioned here above.

For the traffic signs:The basic parts are the shape, color, symbol (number or image).The meaning of a sign is build out of the parts mentioned here above.

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1- Unit two : RepresentationIn this traffic sign example:

Sign (a) is a circle which means an order, its color is blue, and has an image of a bicycle, it is a representation of a road only allowed for bicycles.Sign (b) is also a circle which means an order, its color is red, along with an image of a bicycle, it is a representation of a road prohibited for bicycles.Sign (c) is a triangle which means a warning, its color is red, with an image of a bicycle, it is a representation of a warning that there may be cyclists on the road.

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1- Unit two : Representation

A system where complex representations can be built out of more basic forms, and where the relationship between form and content is predictable, is considered as a language.

Human languages abide by this definition, computer languages also.

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1- Unit two : formats

Computer languages facilitate communication with and between computers.

Formats are a type of computer languages:They represent the detail of the input and output associated with specific applications.They ensure consistency, a document is displayed the same way every time it is opened by a user.They enable sharing, a document is understood by output devices such as printers.

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1- Unit two : formats

There are two types of formats:Proprietary formats protected by copyright laws, usually associated with popular applications for a large user public (ex: Microsoft Word).

Public formats are free, they encourage the development of new applications based on such formats (ex: HTML).

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1- Unit two : formats

Formats are not prefixed, some new formats may emerge, while others follow their evolution, and others even disappear or become obsolete.

New formats appear with new hardware equipment.

New versions of formats allow updated and enhanced features.

Some formats become obsolete because old technologies disappear.

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1- Unit two : format compatibility

In order to ensure compatibility between formats:Either standardize a particular format where a very large group of users agrees to use it .

Or allow conversion between format which means one format can always be translated into another.

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1- Unit two : standardizationDefinitionAdvantages of standardization:

Compatibility ensured between a lot of applications as long as the standard is respected.New formats and standards can evolve together.Users don’t worry about sharing and communicating.The responsibility of ensuring compatibility can be delegated to programmers and doesn’t lie on the user.

Drawbacks:Reduction of the number of formats.A new format evolves slowly into a standard.Adding new features to an existing standard is expensive and time consuming.

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1- Unit two : conversion

DefinitionAdvantages of conversion:

Very beneficial between two standards each respected by a large group of applications.Ability to translate documents from an obsolete format to a current format.

Drawbacks:Inability to map all features of a certain format with another.Difficulty in coping with the evolution of standards and formats as the conversion programs also need to keep track of the evolution.Many standards are currently in use, it is not realistic to develop conversion programs between all of them, gaps will always exist.

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1- Unit two : Representation

File, file name, extension

Allowed characters: some characters are not allowed in the file name depending on the application and the operating system.

A file name needs to reflect in a way the content of the file.

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1- Unit two : extensionsSome extensions:

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2- What’s next

Unit 3: Crossing the boundary: analogue universe, digital world

The world we live in.

Analogue information: digital representation.

Crossing the boundary.

Going back.

What if? … changing the digital world.

Crossing the boundary – a final word.

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3- My questionsIn which ways communication is important for human beings?Explain how the same message can be interpreted in different ways?Is a specific behavior expected during communication?What are the advantages and drawbacks of using email?Does the social background influence the way a representation is interpreted? How?What is Microsoft?What type of formats does Microsoft deal with?What is a freeware?What would you do if you encounter a file of a format unknown to you?Give an example of an obsolete application?Give an example of a format which have evolved into a newer format? Name extensions? Name associated applications?Do different operating systems work with different standards and formats? Elaborate?

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4- Your questions

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