Chapter Understanding and conceptualizing interaction

Based on this analysis, a set of assumptions about the user needs for supporting this activity more effectively were then made. These included:

the bookmarking function was improved users would it more useful and use it more to organize their web addresses.

Users need

a

flexible way of organizing web addresses they want to keep for further reference or for sending on to other people.

A

framework for ex_plicatin_g assumptions

Reasoning through your assumptions about why something might be a good idea enables you to see the strengths and weaknesses of your proposed design. In so doing, it enables you to be in a better position to commence the design process. We have shown you how to begin this, through operationalizing relevant usability goals. In addition, the following questions provide a useful framework with which to begin thinking through the problem space:

Are there problems with an existing product? If so, what are they? Why do you think there are problems?

Why do you think your proposed ideas might be useful? How do you envi- sion people integrating your proposed design with how they currently do things in their everyday or working lives?

How will your proposed design support people in their activities? In what way does it address an identified problem or extend current ways of doing things? Will it really help?

At the turn of the millennium, WAP-enabled (wireless application protocol) phones came into being, that enabled people to connect to the Internet using them. To begin with, the web-enabled services provided were very primitive, being text-based with limited graphics capabilities. Access was very restricted, with the downloaded information being displayed on a very small LCD screen (see Figure 2.2). Despite this major usability drawback, telecommunication company saw this technological breakthrough as an opportunity to cre- ate innovative applications. A host of new services were explored, including text messaging, online booking of tickets, betting, shopping, viewing movies, stocks and shares, sports events and banking.

What assumptions were made about the proposed services? How reasonable are these assumptions?

Figure 2.2 An early cell phone display. Text is restricted to three or four lines at a time and scrolls line by line, making read- ing very cumbersome. Imagine trying to read a page from this book in this way! The newer 3G (third generation) phones have bigger displays, more akin to those provided with handheld computers.

2.3 Conceptual models

39

Comment The problem space for this scenario was very open-ended. There was no identifiable problem that needed to be improved or fixed. Alternatively, the new WAP technology provided op- portunities to create new facilities and experiences for people. One of the main assumptions is that people want to be kept informed of up-to-the-minute news sports, stocks and share prices) wherever they are. Other assumptions included:

That people want to be able to decide what to do in an evening while on their way home from work checking listings, movies, making restaurant reservations). That people want to be able to interact with information on the move reading

on the train).

That users are prepared to put up with a very small display and will be happy browsing and interacting with information using a restricted set of commands via a small number of tiny buttons.

That people will be happy doing things on a mobile phone that they normally do using their reading surfing the web, playing video games, doing their shopping).

It is reasonable to assume that people want flexibility. They like to be able to find out about news and events wherever they are (just look at the number of people who take a radio with them to a soccer match to find out the scores of other matches being played at the same time). People also like to use their time productively when traveling, as in making

phone calls. Thus it is reasonable to assume they would like to read and send on the move. The most troublesome assumption is whether people are prepared to interact with the range of services proposed using such a restricted mode of interactivity. In particular, it is questionable whether most people are prepared to give up what they have been used to large screen estate, ability to type messages using a normal-sized keyboard) for the flexibility of having access to very restricted Internet-based information via a cell phone they can keep in their pocket.

One of the benefits of working through your assumptions for a problem space before building anything is that it can highlight problematic concerns. In so doing, it can identify ideas that need to be reworked, before it becomes too late in the de- sign process to make changes. Having a good understanding of the problem space can also help greatly in formulating what it is you want to design. Another key as- pect of conceptualizing the problem space is to think about the overall structure of what will be built and how this will be conveyed to the users. In particular, this in- volves developing a conceptual model.

2.3

Conceptual models

"The most important thing to design is the user's conceptual model. Everything else should be subordinated to making that model clear, obvious, and substantial. That is almost exactly the opposite of how most software is designed." (David Liddle,

Chapter Understanding and interaction

By a conceptual model is meant:

a 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.

To develop a conceptual model involves envisioning the proposed product, based on the users' needs and other requirements identified. To ensure that it is designed to be understandable in the manner intended requires doing iterative testing of the product as it is developed. A key aspect of this design process is initially to decide what the users will be doing when carrying out their tasks. For example, will they be primarily searching for information, creating documents, communicating with other users, recording events, or some other activity? At this stage, the interaction mode that would best support this needs to be considered. For example, would al- lowing the users to browse be appropriate, or would allowing them to ask questions directly to the system in their native language be more effective? Decisions about which kind of interaction style to use whether to use a menu-based system, speech input, commands) should be made in relation to the interaction mode. Thus, decisions about which mode of interaction to support differ from those made about which style of interaction to have; the former being at a higher level of abstraction. The former are also concerned with determining the nature of the users' activities to support, while the latter are concerned with the selection of specific kinds of interface.

Once a set of possible ways of interacting with an interactive system has been identified, the design of the conceptual model then needs to be thought through in terms of actual concrete solutions. This entails working out the behavior of the interface, the particular interaction styles that will be used, and the "look and feel" of the interface. At this stage of "fleshing out," it is always a good idea to explore a number of possible designs and to assess the merits and problems of each one.

Another way of designing an appropriate conceptual model is to select an in- terface metaphor. This can provide a basic structure for the conceptual model that is couched in knowledge users are familiar with. Examples of well-known interface metaphors are the desktop and search engines (which we will cover in Section 2.4). Interaction paradigms can also be used to guide the formation of an appropriate conceptual metaphor. They provide particular ways of thinking about interaction design, such as designing for desktop applications or ubiquitous computing (these will also be covered in Section 2.5).

As with any aspect of interaction design, the process of fleshing out conceptual models should be done iteratively, using a number of methods. These include sketching out ideas, describing possible scenarios, and prototyping aspects of the proposed behavior of the system. All these methods will be covered in Chapter 8, which focuses on doing conceptual design. Here, we describe the dif- ferent kinds of conceptual models, interface metaphors, and interaction paradigms to give you a good understanding of the various types prior to thinking about how to design them.

2.3 Conceptual models

41

There are a number of different kinds of conceptual models. These can be bro- ken down into two main categories: those based on activities and those based on objects.

2.3.1

Conceptual models based on activities

The most types of activities that users are likely to be engaged in when in- teracting with systems are:

1. instructing 2. conversing

3. manipulating and navigating

In document Interaction Design Beyond Human Computer Interaction (1st edition) pdf (Page 69-72)