MIS, PROTOTYPING
What is evolutionary development?
Deliberately choosing a malleable software platform, building software in incremental, iterate fashion
Characteristics of Incremental prototyping
separate prioritised functions merged into final design gradually
What are index cards?
they are 3 by 5 inches cards each representing a screen often used in web development
What are the quick ways of creating or building a prototype?
- The data entry form -The menu structure and order -The dialogue styles -Error messages
Importances of prototyping?
- To save on time and money -To have something that can be tested by real users - Allows stakeholders to interact with the envisioned product, gain experience on imagined uses.
What are the examples of a prototype?
-A series of screen sketches -A storyboard -A powerpoint slide show -A video simulating the use of a system -piece of software with limited functionality written in the target or another language
What are the advantages of low fidelity?
-Basis for final product -proof of concept -use of low cost, non-electronic media -Evaluate multiple design concepts
How to Prototype
-Build the prototype of the basic functionality (interface) -Test it -Correct errors -Repeat until you have a clean design
How does one prototype for usability?
-Design typical user task scenarios -Identify tasks based on the scenario -use real users to test -Watch user performing task -iterate design based in test
Characteristics Horizontal prototyping
-Displays breadth of functionality , no lower level detail "back end" Support Ex. -Broad and shallow -Overview with limited underlying functionality -simulation of entire interface
What are characteristics of low fidelity?
-Does not look much like the final product -uses material that are different from intended version e.g paper -used in early stages of development -cheap and easy to modify and explore other designs and ideas -They are for exploration purposes
Goals for prototyping
-Exploring requirements -Choosing among alternatives -Empirical usability testing -Evolutionary development
What are other prototyping techniques?
-Full prototype, has full functionality lower performance than software -Horizontal prototype, displays breadth of functionality, no longer level detail support Ex. -Vertical prototype, full functionality, full functionality and performance of a small part of the system.
What are The fidelity spectrums?
-High fidelity -Low fidelity
What are the two types of compromises?
-Horizontal compromise -Vertical compromise
What are the pitfalls of prototyping
-It is a slow process
Why prototype?
-It is a tool for improving usability - It encourages reflection -Prototypes answer questions and help in choosing between alternatives -Stakeholders can see, hold and interact more easily with prototype than document or idea -You can test for ideas -Team members communicate effectively -Evaluation and feedback are central to interaction design - For traditional software development
General features of prototyping?
-It should enable the designer to quickly build or create -Should be inexpensive to develop -Should not require programming skills
What are the disadvantages of low fidelity?
-Limited error checking -It has navigational and flow limitations
How to present prototypes
-Mockup -Storyboard -Sketches -Scenarios -Screenshots -Functional interface
What are the disadvantages of High fidelity?
-More expensive to develop -time consuming to build -developers are reluctant to change something they have crafted for hours
Disadvantages of horizontal prototyping
-Not possible to perform real work -Users cannot interact with real data -Often possible to create a wish list interface
What are the compromises of high fidelity?
-Slow response -sketchy icons -limited functionality available
Examples of low fidelity prototyping
-Storyboards -Sketching -Index cards -Wizard of Oz
What to prototype?
-Technical issues -Work flow, task design -Screen layouts and information display -Difficult, controversial, critical areas
What are advantages of prototyping early on costs?
-Testing early often makes the product cheaper -testing usability is cheaper
Benefits of prototyping?
-Tests details of final product before it s built. -Results in higher user satisfaction -Users are better at evaluating an existing system -It brings the users into early
What is the advantage of vertical prototype?
-There is full functionality and performance of a slice or small part of a system. -Reduction of number of features -in-depth functionality for a few selected features -tests part of a system -tests in depth under realistic circumstance with real user tasks
Characteristics of Throwaway or rapid prototyping
-Used exclusively in requirements gathering -built, used and thrown away -knowledge gained contributes to final system -It is used to get the specs right, then discarded.
Disadvantages of prototyping?
-Users may be unfamiliar with the technique -If the prototype is too good management may think that the project is nearly finished or convert into final product.
Evolutionary Prototyping
-Will become the final program. This model evolves until the model is done -not discarded but serves as basis for the next iteration of the design
Why is prototyping important in Traditional software development?
-You can not test the software until it is implemented with effort and scheduled time because it is expensive -software design errors are built into the first ting you built and are usually left in the product if they are not that bad.
How to overcome pitfalls of prototyping?
-You need a good starting point -You need to understand what is wrong when things go sideways
Advantages of horizontal prototyping
-can be created quickly -Gives an idea of how the interface will hang together identifies top level functionality
What are characteristics of a high fidelity spectrum?
-close to final product in appearance not function because of use of same materials -Electronically faithful -Uses similar development environments like Macromedia Director -May mislead users into thinking it is the final product
Prototyping Process
-establish prototype objectives by making a prototyping plan
What is the advantages of high fidelity
-fully interactive - users get the look and feel of the final product -clearly defines navigating schemes
Prototyping techniques
-storyboards -paper prototypes -Wizard of Oz -Software prototypes
Why is it important to test the interface with real users?
-the feedback helps with the development process -life cycles give us a way to feed what we discover back into the development process
What is meant by exploring requirements?
making a market analysis, participatory design
Prototyping approaches
-Throwaway vs Evolutionary incremental -Horizontal vs vertical -low vs high fidelity
What qualities must be attended to during the construction period?
-Usability -Reliability -Robustness -Maintainability -Integrity -Portability -Efficiency
What is meant by choosing among alternatives?
Choosing between risky or critical features and making go/no-go decisions
What are the advantages of mockups or wireframes?
-Good for brainstorming -Focuses on high level design notions
What is an interface
A device or program enabling a user to communicate with a computer. Interconnections between systems.
What is fidelity?
This is the degree to which a prototype accurately represents the appearance and interaction of the product.
What are sketches?
Drawings of the outward appearance of the high level concepts of the intended system
What is a storyboard?
It is a series of key frames as sketches originally used films to generate ideas of the direction in this case of the interface
What is a Mockup
It is an arrangement of text or pictures showing as much necessary detail
What is the cost of prototyping?
It is cheaper to do a prototype than it is to not have because error made in analysis and design phase can cost 100 times more
How much should prototyping cost?
It should amount to 5-10% of the project's budget
What is the construction process?
Taking prototypes, learning from them and creating a whole finished product
What are the compromises in low fidelity?
The device doesn't actually work
What is the weakness of evolutionary prototype?
There is danger of initially bad designs persisting
What are vertical compromises?
These provide a lot of detail for only a few functions
What are horizontal compromises?
These provide a wide range of functions but with little detail
What is the other name of low fidelity prototypes?
They are also known as Wireframe
What are the disadvantages of Mockups or wireframes?
They are not good for illustrating flow and the details
What does it mean to prototype for usability?
This refers to prototyping for ease of use of an application
What are compromises?
To accept standards that are lower than is desirable
What is meant by empirical usability testing?
Trying out ideas with target users as early as possible
What is wizard of oz prototyping?
User thinks they are interacting with a computer but really it is the wizard who is part of design team.
Disadvantage of vertical prototyping
Users cannot move freely through the system
What is a prototype?
a test model of a product that allows users to interact with it and explore its suitability
Why must one avoid the temptation to build the final product from Hi-Fi prototypes?
because Low fidelity prototypes allow everyone involved from users to key stakeholders to iterate on lots of ideas; try out features; and imagine different layers of customization and interactivity.
Prototyping
design ---> Prototype ---> evaluate ---> (if its okay you are done if not) ---> re-design ---> prototype ---> evaluate then repeat if not okay
Early prototyping v Late prototyping
early prototyping is used to evaluate function and interface whilst late prototyping is used to evaluate performance
What is evaluation?
it is the comparison of an prototype of interest against a standard of acceptability