Prototyping Teppo Räisänen

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

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

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)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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