In the process of creating an interactive product, it can be tempting to begin at the “nuts and bolts” level of the design.
Understanding the problem space :
- What do you want to create?
- What are your assumptions?
- Will it achieve what you hope it will?
A problem with trying to solve a design problem beginning at this level is that critical usability goals and user needs may be overlooked.
A problem in starting to solve a design problem at the physical level: usability goals can be easily overlooked.
While it is certainly necessary at some point to decide on the design of physical aspects. It is better to make these kinds of design decisions after understanding the nature of the problem space:
- Conceptualizing what you want to create and articulate why you want to do so.
- This requires thinking through how your design will support people in their everyday or work activities.
- Need to ask yourself whether the interactive product you have in mind will achieve what you hope it will. HOW?
Clarifying your usability and user experience goals is a central part of working out the problem space.
Making explicit your implicit assumptions and claims.
Assumptions that are found to be vague can highlight design ideas that need to be better formulated. This involves identifying human activities and interactivities that are problematic and working out how they might be improved through being supported with a different form of interaction. In other situations it can be more speculative, requiring thinking through why a novel and innovative use of new technology will be potentially useful.
A framework for analyzing the problem space :
- Are there problems with an existing product?
- Why do you think there are problems?
- Why do you think your proposed ideas might be useful?
- How would you see people using it with their current way of doing things?
- How will it support people in their activities?
- Will it really help them?
Having a good understanding of the problem space can help inform the design space, but before deciding upon these it is important to develop a conceptual model.
Conceptual Model
A conceptual model is a high-level description of:
“The proposed system in terms of a set of integrated ideas and concepts about what it should do, behave and look like, that will be understandable by the users in the manner intended.”
The first step in formulating a conceptual model :
- What will the users be doing when carrying out their tasks?
- How will the system support these?
- What kind of interface metaphor, if any, will be appropriate?
- What kinds of interaction modes and styles to use?
Always keep in mind when making decisions how the user will understand the underlying conceptual model.
Conceptual models based on activities :
1. Giving instructions
Where users instruct the system and tell it what to do
- Issuing commands using keyboard and function keys and selecting options via menus (tell the time, print a file, save a file).
The main benefit is that instructing supports quick and efficient interaction.
2. Conversing
The underlying model of having a conversation with another human, range from simple voice recognition menu-driven systems to more complex ‘natural language’ dialogues.
- Interacting with the system as if having a conversation (timetables, search engines, advice giving systems, help systems).
3. Manipulating and navigating
Involves dragging, selecting, opening, closing and zooming actions on virtual objects, exploits user’s knowledge of how they move and manipulate in the physical world.
- Acting on objects and interacting with virtual objects. (WYSIWYG and Direct Manipulation approach).
- Shneiderman (1983) coined the term DM, came from his fascination with computer games at the time.
Core principles of DM:
- Continuous representation of objects and actions of interest.
- Physical actions and button pressing instead of issuing commands with complex syntax.
- Rapid reversible actions with immediate feedback on the object of interest.
Why are DM interfaces so enjoyable?
- Novices can learn the basic functionality quickly
- Experienced users can work extremely rapidly to carry out a wide range of tasks, even defining new functions.
- Intermittent users can retain operational concepts over time.
- Error messages rarely needed.
- Users can immediately see if their actions are furthering their goals and if not do something else
- Users experience less anxiety.
- Users gain confidence and mastery and feel in control.
4. Exploring and browsing
Similar to how people browse information with existing media (e.g. newspapers, magazines, libraries, pamphlets).
Information is structured to allow flexibility in the way a user is able to search for information (e.g. multimedia, web).
- Finding out and learning things.
Activity
What conceptual models are the following applications based on?
A 3D video game, say a car-racing game with a steering wheel and tactile, audio, and visual feedback.
Comments:
A 3D video game is based on a direct manipulation/virtual environment conceptual model.
1. The windows environment.
Comments:
The windows environment based on a hybrid form of conceptual model.
It combines a manipulating mode of interaction where users interact with menus, scrollbars, documents and icons, an instructing mode of interaction where users can issue commands through selecting menu options and combining various function keys, and a conversational model if interaction where agents (e.g Clippy) are used to guide users in their actions.
2. A web browser.
Comments:
A web browser is also based on a hybrid form of conceptual model, allowing users to explore and browse information via hyperlinks and also to instruct the network what to search for and what result to present and save.
Which conceptual model is best ?
- Direct manipulation is good for ‘doing’ types of tasks, e.g. designing, drawing, flying, driving, sizing windows.
- Issuing instructions is good for repetitive tasks, e.g. spell-checking, file management.
- Having a conversation is good for children, computer-phobic, disable users and specialized applications (e.g. phone services).
- Hybrid conceptual models are often employed, where different ways of carrying out the same actions is supported at the interface — but can take longer to learn.
Interface metaphors
Interface designed to be similar to a physical entity but also has own properties (e.g. desktop metaphor, web portals).
Can be based on activity, object or a combination of both.
Exploit the user’s familiar knowledge, helping them to understand ‘the unfamiliar’.
Conjures up the essence of the unfamiliar activity, enabling users to leverage this to understand more aspects of the unfamiliar functionality.
The benefit of interface metaphors :
- Makes learning new systems easier.
- Helps users understand the underlying conceptual model.
- Can be very innovative and enable the realm of computers and their applications to be more accessible to a greater diversity of users.
Problems with interface metaphors :
- Break conventional and cultural rules (e.g. recycle bin placed on desktop).
- Can constrain designers in the way they conceptualize a problem space.
- Conflict with design principles.
- Forces users to only understand the system in terms of the metaphor.
- Designers can inadvertently use bad existing designs and transfer the bad parts over.
- Limits the designer’s imagination in coming up with new conceptual models.
Interaction mode:
What the user is doing when interacting with a system, e.g. instructing, talking, browsing or other.
Interaction style:
The kind of interface used to support the mode (e.g. speech, menu-based, gesture).
Many kinds of interactions styles available …
(e.g. command, speech, data-entry, form fill-in, query, graphical, web, pen, augmented reality, gesture, and even…)
Which interaction style to choose?
- Need to determine requirements and user needs.
- Take the budget and other constraints into account.
- Also will depend on the suitability of technology for the activity being supported.
- This topic will be covered later when discussing how to actually design conceptual models.
Examples of new paradigms:
- Ubiquitous computing (mother of them all).
- Pervasive computing.
- Wearable computing.
- Tangible bits, augmented reality.
- Attentive environments.
- Transparent computing, etc…
Summary points:
- Important to have a good understanding of the problem space.
- Fundamental aspects of interaction design are to develop a conceptual model.
- Interaction modes and interface metaphors provide a structure for thinking about which kind of conceptual model to develop.
- Interaction styles are specific kinds of interfaces that are instantiated as part of the conceptual model.
- Interaction paradigms can also be used to inform the design of the conceptual model.
