Requirements & Interaction Styles 9-17-2012 Establishing - - PowerPoint PPT Presentation

Requirements & Interaction Styles 9-17-2012

 Establishing Requirements  Selecting an Interaction Style

Activity#2 due today, 9/17/12

 Select your project topic & team

HW#2 posted, due Wednesday 9/19 Activity#3 due Monday, 9/24/12

 Select your presentation topic

PR#1 posted, due Monday, 10/08

Describe the conceptual model underlying the two vending machines. Which is easiest to use?

 Start with Usability Goals & User Experience Goals

Generate Usability Criteria in the form of

questions  Identify the User’s Conceptual Model

Are there relevant metaphors? How do people interact with the product?

• 1. Identifying needs and establishing

requirements for the user experience

• 2. Developing alternative designs to meet

these

• 3. Building interactive prototypes that can be

communicated and assessed

• 4. Evaluating what is being built throughout

the process and the user experience it

• ffers

 What

Two aims:

• 1. Understand as much as possible about

users, task, context

• 2. Produce a stable set of requirements

 How



Data gathering activities



Data analysis activities



Expression as ‘requirements’



All of this is iterative

 Why:

Requirements definition: the stage where failure occurs most commonly

Getting requirements right is crucial !!

 What do users want? What do they ‘need’?

 Requirements need clarification, refinement,

completion, re-scoping

 Input: requirements document (maybe)  Output: stable requirements

 Why ‘establish’?

 Requirements arise from understanding users’

needs

 Requirements can be justified & related to data

 Functional:

 What the system should do

 Historically the main focus of requirements

activities (Non-functional: memory size, response time, physical constraints, ... )

 Data:

 What kinds of data need to be stored?  How will they be stored (e.g. database)?

 Environment or context of use:

 physical: dusty? noisy? vibration? light?

heat? humidity? …. (e.g. ATM)

 social: sharing of files, of displays, in paper,

across great distances, work individually, privacy for clients

 organizational: hierarchy, IT department’s

attitude and remit, user support, communications structure and infrastructure, availability of training

http://wetpc.com.au/html/products/mobile.htm

KordGrip

 Users: Who are they?

 Characteristics: ability, background,

attitude to computers

 System use: novice, expert, casual, frequent  Novice: step-by-step (prompted),

constrained, clear information

 Expert: flexibility, access/power  Frequent: short cuts  Casual/infrequent: clear instructions, e.g.

menu paths

 Usability Goals  User Experience Goals

Suggest one key functional, data, environmental, user and usability requirement for a Clarkson Student Center information kiosk

“Most users are neither beginners nor experts; instead, they are intermediates.” – Cooper, About Face 2.0, p. 33  “Optimize for intermediates”

• 1. Rapidly and painlessly help beginners achieve

intermediacy.

• 2. Avoid putting obstacles in the way of those

intermediates who want to become experts.

• 3. Keep perpetual intermediates happy as they

stay in the middle of the skill spectrum.

 “Nobody wants to remain a beginner.”  Imagine that users are simultaneously very intelligent and very busy. They need some instruction or aid, but the process must be rapid and targeted.  A newbie must grasp the concepts and scope of the program quickly => ensure that the software reflects the user’s mental model of the tasks

 standard on-line help is insufficient for this  a separate dialog box may be helpful to communicate

• verview, scope and purpose

 beginners rely heavily on menus to learn commands

 Perpetual intermediates need access to tools

tooltips online help

 Intermediates develop a frequently used working set of features  May know that advanced features exist, but may not need them or know how to use them

 Direct Manipulation  Menu selection  Form fillin  Command language  Natural language

 Instruc ructing ing

 issuing commands using keyboard and function

keys and selecting options via menus

 Conver ersing sing

 interacting with the system as if having a

conversation

 Manip ipulat ulating ing

 interacting with objects in a virtual or physical

space by manipulating them

 Ex Explo loring ring

 moving through a virtual environment or a

physical space

 Where users instruct a system by telling it what to do

 e.g., tell the time, print a file, find a photo

 Very common interaction type underlying a range of devices and systems  A main benefit of instructing is to support quick and efficient interaction

 good for repetitive kinds of actions performed on

multiple objects

 Like having a conversation with another human  Differs from instructing in that it more like two-way communication, with the system acting like a partner rather than a machine that obeys orders  Ranges from simple voice recognition menu- driven systems to more complex ‘natural language’ dialogues  Examples include search engines, advice- giving systems and help systems

 Allows users, especially novices and technophobes, to interact with the system in a way that is familiar

 makes them feel comfortable, at ease and less

scared  Misunderstandings can arise when the system does not know how to parse what the user says

 Exploit’s users’ knowledge of how they move and manipulate in the physical world  Virtual objects can be manipulated by moving, selecting, opening, and closing them  Tagged physical objects (e.g., bricks, blocks) that are manipulated in a physical world (e.g., placed on a surface) can result in other physical and digital events

 Shneiderman (1983) coined the term Direct Manipulation  Came from his fascination with computer games at the time  Proposes that digital objects be designed so they can be interacted with analogous to how physical objects are manipulated  Assumes that direct manipulation interfaces enable users to feel that they are directly controlling the digital objects

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Raffle, Yip & Ishii Mit media lab http://web.media.mit.edu/~hayes/topobo/index.html