This document discusses different types of prototypes that can be used during product development. It describes paper prototypes as being easy, fast and cheap to produce. Functional prototypes implement some or all features to test functionality but cut costs by reducing features, functionality or resources. Simulation mimics a product's actual user interface while emulation imitates functions on different hardware. The document advises that after testing, prototypes should be discarded rather than having their code used in the final product.

1. Prototyping
Teppo Räisänen
http://www.oamk.fi/~teraisan/
Teppo.raisanen@oamk.fi

2. 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

3. 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

4. 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)

5. 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

6. 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

7. 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

8. Functional Prototypes
1. Cut down the product features
 only part of all features are implemented
 the implemented features are fully
functional
2. Cut down the functionalities
 all features are implemented
 some functionalities are missing

9. Functional Prototypes
3. 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

10. Functional Prototypes
 Often mixtures of aforementioned
methods are used to cut down the costs
of developing a prototype

11. 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 user’s actions

12. 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

13. 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 => mobile device
 Cardbroad box => laptop computer
 Pencil => bar code reader

14. 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

15. 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

16. 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

17. Wizard of Oz
 In reality user’s 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
system’s actions

18. Emulation Techniques
 Emulation = imitating a product’s
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 device’s UI before hardware
examples are manufactured

19. Emulation Techniques
 Emulator’s do not transmit a truthful
image of a product, e.g.
 no physical buttons of the actual device
 different display format

20. 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

21. 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
user’s actions

22. 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

23. 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

24. 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

25. 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

26. 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 prototype’s code
to be used is to implement prototype
with a language unsuitable for for the
product