Prototyping

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Prototyping

• Teppo Räisänen
• http//www.oamk.fi/teraisan/
• Teppo.raisanen_at_oamk.fi

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General Information

• Prototyping is commonly used as a part of
  user-centered design paradigms
• Prototyping was introduced during 1980s
• Prototyping has a strong position in Contextual
  Design method

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General Information

• What is a prototype?
• Looks like a finished product?
• Behaves like a finished product?
• May have small faults or missing functionalities?
• Prototypes can be used in many ways
• To try out new features of an application
• Test a complete family of applications

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Prototyping vs. Traditional methods

• According to some sources prototyping does not
  fit very well in waterfall design paradigm
• results of intermediate phases are not suitable
  for prototyping
• In waterfall model it is expensive to go back a
  step (e.g. from implementation back to design)

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Prototyping vs. Traditional methods

• An experienced usability expert will be able to
  see some of the usability issues from the
  documentation
• This kind of practice is, however, inadequate
• Many usability issues will not be found
• One solution is to separate UI design to an
  independent subproject

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Prototyping vs. Traditional methods

• Especially important is to use prototyping, when
  new product concepts are introduced
• Prototypes can also be used as a means of
  communication between project units
• Often parts of requirements spesification are
  intepreted in different ways
• Prototypes are useful for completing formal
  spesifications

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Functional Prototypes

• Functional protoype is essentially a product with
  fully implemented functionalities
• The goal is still to keep the costs lower than
  those of a finished product
• There are basically three ways to cut the
  expenses

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Functional Prototypes

• Cut down the product features
• only part of all features are implemented
• the implemented features are fully functional
• Cut down the functionalities
• all features are implemented
• some functionalities are missing

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Functional Prototypes

• Cut down resources used in implementation
• Memory optimization is not implemented
• Efficency is not maximized
• Very effective computers are used during testing
  to make up missing efficency
• Error hanling is not fully implemented

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Functional Prototypes

• Often mixtures of aforementioned methods are used
  to cut down the costs of developing a prototype

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Paper Prototypes

• In some cases it is practical to use paper
  prototypes instead of functional ones
• E.g. Contextual Design stresses use of paper
  prototypes
• Piece of paper is used to represent UI
• A member of usability staff arranges the UI
  according to users actions

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Paper Prototypes

• Changes to the UI can be illustrated by
• Using Post-it labels
• Drawing to the paper
• Using various pieces of paper
• The person responsible for arranging the UI must
  know the underlying system well

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Paper Prototypes

• E.g. heuristic evaluation methods can be used
• We will go into heuristics later in the course
• Use of paper prototypes is not restricted to just
  desktop applications
• Wood block gt mobile device
• Cardbroad box gt laptop computer
• Pencil gt bar code reader

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Paper Prototypes

• Various software tools can be used to sketch the
  contents of paper prototypes, e.g.
• Visual Basic for the UI views
• Flash for mobile device emulations
• It may be psychologically easier for the test
  person to suggest changes to a ballpark drawing

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Paper Prototypes

• Compared to functional prototypes, paper
  prototypes are easier, faster and cheaper to
  produce
• Several degrees of accuracy can be used during
  iterative cycles

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Wizard of Oz

• Wizard of Oz is a spesific technique of
  prototyping
• Used to test and demonstrate technically
  impossible features
• E.g. speech recognizing text editor in 1970s
• User believes he/she is using a computer-based
  system

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Wizard of Oz

• In reality users actions are transmitted to a
  person, who processes actions and forms the
  feedback of the system
• Because of that, the response times can be quite
  long
• User can be told, that advanced processes are
  time-comsuming
• Several wizards can be used to speed up
  systems actions

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Emulation Techniques

• Emulation imitating a products functions using
  another product
• E.g. mobile devices can be emulated using desktop
  computers
• More processing power, thus no need for code
  optimization
• Ability to test devices UI before hardware
  examples are manufactured

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Emulation Techniques

• Emulators do not transmit a truthful image of a
  product, e.g.
• no physical buttons of the actual device
• different display format

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Simulation Techniques

• Simulations are used to mimic a device by using
  another kind of technical enviroment
• E.g. flight simulators used for pilot training
• The difference between simulation and emulation
  is, that simulation utilizes the actual UI of a
  device

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Simulation Techniques

• Simulation can be used during early design phases
  of a product, e.g.
• Model can be made of wood or plastic
• The hardware buttons are included in the model
• Buttons are wired to a computer system, which
  gives feedback according to the users actions

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Simulation Techniques

• Simulations are effective means of
• marketing a product
• localization
• testing the physical adequacy of the product
• Simulations are generally more expensive than
  other forms of prototyping

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Manuscripts

• A manuscript (like in a case of a movie) can be
  written of a product
• Manuscript will represent a spesific task, which
  is completed by using the product
• The goal is to demonstrate the product in daily
  use and advantages of using the product

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Manuscripts

• Suitable formats of manuscripts are
• animations
• comic strips
• theater plays
• etc.
• Manuscripts are not to be used as testing methods
• Instead they are good for demonstrating a product
  to a large audience

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After Prototype Has Been Used

• Usually the best choice is to throw the prototype
  away
• It is meant to be used as a sketch
• There are many real-world examples of failures,
  when code parts of prototypes have been used in
  products

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After Prototype Has Been Used

• Prototypes, which look too good can be
  potentially dangerous
• Customer may think, that the product is almost
  finished
• Management is not willing to throw almost
  finished parts of prototype away
• One way of avoiding prototypes code to be used
  is to implement prototype with a language
  unsuitable for for the product