link to find out about accessibility of websites

Link to find out about accessibility of websites

http://web-support.csx.cam.ac.uk/access/accessibility.pdf

Methods foruser-centered design

Participatory Design:

The now widely recognised idea to involve the users in the development of a system for improved usability of the interface.

This is typically successful because users can give designers their own opinions and make useful suggestions, which can help to prevent errors in the first place before they occur.

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continuedParticipatory Design continued:

The design should be able to anticipate potential problems by interacting with users during the design phase.

This has led to a design that makes erroneous choices unavailable (greying out menu choices or buttons if they are not available, e.g. if you haven’t copied anything, you cannot paste).

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continuedParticipatory Design continued:

The design should attempt a good compromise for both new and experienced users. Therefore, both novices and experts should be involved during the design phase of new applications.

Methods foruser-centered design

continuedDifferent Methods for user-centered design:

1. Soft Systems Methodology

2. Cooperative Design

3. Multiview

4. The star life cycle

Methods foruser-centered design

continued1. Soft Systems Methodology

Many HCI researchers consider a holistic point of view as necessary. This means that is is important to understand the whole human-computer system and to put it into a wider context, e.g. many human actions depend on the situations humans currently experience.

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continued1. Soft Systems Methodology continued

One of the most popular holistic point of views was given the name “Soft Systems Methodology” (Checkland, 1981).

The idea of the Soft Systems Methodology is to understand the particular situation in which the problem is believed to lie and not to just find a general solution to a specified problem.

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continued1. Soft Systems Methodology continued

Therefore, this approach first tries to define the situation (stages 1 and 2). The definition of the situation occurs in 2 stages. First, a problem situation is perceived and in stage 2, a better overview is gained by having the problem situation expressed through communication with all involved parties.

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continued1. Soft Systems Methodology continued

After expressing the problem in the given situation, the approach tries to deliver a precise definition (“root definition”) of the system (stage 3), which is applied to produce conceptual models (=abstract representations) of the system.

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continued1. Soft Systems Methodology continued

These conceptual models in stage 4 include the consideration of clients/customers, actors, transformations, world view, owners and the environment. The precise root definition from stage 3 will have already identified who all the involved people are (i.e. the clients, the actors who use the system and the owners of the system).

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continued1. Soft Systems Methodology continued

Stages 3 and 4 are typically abstract modeling processes that do not relate directly to the specific situation at hand, i.e. many scenarios can be considered and simulated. This is an abstract modeling process that does not take place in the real world (though the people from the problem definition in stage 3 are real).

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continued1. Soft Systems Methodology continued

Stages 5, 6 and 7 then go away from the abstract point of view and try to embed the earlier processes into the real world (the concrete situation at hand).

Stage 5 will expose gaps in the original root definition after incorporating the expressed situational circumstances until a well-formed...

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continued1. Soft Systems Methodology continued

...root definition has been found.

In Stage 6, the conceptual model of the situation is compared with the original expression of the situation (= the situation before communication took place between all involved parties and before the situation was expressed through this communication).

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continued1. Soft Systems Methodology continued

it is possible that Stage 6 exposes further changes that might be necessary.

In Stage 7, action takes place to improve the situation at hand with the help of the designed system, but this may not succeed in the first place, so many iterations might be necessary.

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continued1. Soft Systems Methodology continued

Soft Systems Methodology has been highly influential. Applied to designing HCI systems and good user interfaces, the main focus is on combining the actual purpose, the people involved, the technical and human constraints, the world view of the people. This helps to develop adequate conceptual models of all involved people and system components so that the goals of delivering a good system can be achieved.

Methods foruser-centered design

continued2. Co-operative Design

...involves several approaches. They all have in common that users participate in the design process.

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continued2. Co-operative Design continued

I will refer to 3 (overlapping) approaches:

1. Participatory design (=Scandinavian Approach)

2. Socio-technical design

3. Open System Task Analysis (OSTA)

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continued2. Cooperative Design continued

Participatory Design aims to improve the working conditions and the working environment of the user. It involves full collaboration with users and repeated prototyping, workshops, etc.

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continued2. Co-operative Design continued

Participatory Design involves participation of the user in analysing organisational requirements and planning social as well as technical structures that would benefit both the employee and the organisation.

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continued2. Co-operative Design continued

The advantage of Participatory Design is that it is likely to produce a workable and usable system for all its users. The disadvantage is that it is often difficult to control the cost of this approach and that it requires some time to implement in a satisfactory way.

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continued2. Co-operative Design continued

Socio-technical Design focuses on the entire human-computer system and aims to find designs that are both socially and technically feasible. This is a difficult problem, because this involves many elements (e.g. the different models of tasks, domains and systems that users and designers deal with).

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continued2. Co-operative Design continued

In order to deal with these difficulties of incorporating all these elements, Socio-technical Design focuses on a wide range of methodologies for system design, analysis and design techniques and evaluation methods.

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continued2. Co-operative Design continued

One example of a methodology that is based on a socio-technical design is the Open System Task Analysis (OSTA).

The aim of OSTA is to deliver a methodology that helps understand what transformation occurs when a new computer system is introduced into a working environment.

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continued2. Co-operative Design continued

In summary, co-operative design approaches involve users to actively participate in the design process.

In order to avoid problems when relying on Co-operative Design approaches, a number of suggestions have been made.

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continued2. Co-operative Design continued

One suggestion is to rely on expert advice during the design process, because experts have long experience which helps them guide the design process and support users.

Another suggestion is to only rely on co-operative design if the management is committed to involve users and to accept their requirements.

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continued2. Co-operative Design continued

Another problem that has been pointed out is that none of these methods inform designers how they can involve users.

Methods foruser-centered design

continued3. Multiview

...is an information systems design methodology that combines the approaches from soft systems methodology and co-operative design into a staged and controlled methodology (i.e. it defines an order of steps that need to be carried out).

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continued3. Multiview continued

Multiview begins with an analysis of human activities. This results in the Primary Task Model (PTM). Furthermore, a conceptual model is developed. After all this has taken place, decisions about the actual design implementation are made.

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continued3. Multiview continued

Consequently, Multiview provides more direction for system designers by referring to the different steps in the design process. Multiview is a complete methodology and spans from the planning of the design to its actual implementation.

Methods foruser-centered design

continued4. The Star Life Cycle

The Star Life Cycle is based on the actual design practice of User Interface Design practitioners. In contrast to the structured Mulitiview methodology, the Star Life Cycle assumes that ordering of activities and processes is inappropriate to User Interface Design.

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continued4. The Star Life Cycle continued

Hence, the Star Life Cycle expresses more accurately what the designers really do and places a high weight on evaluation, i.e. both users and experts should evaluate the design development constantly.

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continued4. The Star Life Cycle continued

By relying on what designers really do rather than what they should do according to the more structured Multiview approach, one could also say that the Star Life cycle adopts an approach that is more experimental, more flexible and less structured than the traditional approaches such as Multiview or the Waterfall model.

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continued4. The Star Life Cycle continued

The Star Life Cycle is often described to adopt an alternating waves approach, which is adding a flexible bottom-up approach to the more traditional, well-structured top-down approach known from Multiview and the Waterfall model.

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continued4. The Star Life Cycle continued

The Star Life Cycle approach recommends rapid prototyping, constant evaluation of the product and step-by-step development and refinement until the final outcome is reached.

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continued4. The Star Life Cycle continued

This flexibility has several advantages in the rapidly changing field of multimedia. The reason for this is that in the course of developing a device, there might be necessary changes that were initially not considered but that need to be implemented in order to bring this device up to date.

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continued4. The Star Life Cycle continued

The main stages in the star life cycle consist of similar activities as the stages in the Waterfall model:

Analysis, Requirements specification, Design, Implementation.

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continued4. The Star Life Cycle continued

However, in the Star Life Cycle, system development may begin at any stage (uni-directional arrows) and may be followed by any of the other stages (bi-directional arrows).

A figure to illustrate this can be found on the next slide.

The Star Life Cycle

Evaluation

Task Analysis

Requiremens Specification

Conceptual Design/Formal

Design

Prototyping

Implementation

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continued4. The Star Life Cycle continued

The Star Life Cycle process also involves a lot more iteration than the Waterfall and Life Cycle Approach. The requirements, design and the product gradually evolve and become increasingly well defined.

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continued4. The Star Life Cycle continued

The Star Life Cycle makes a distinction between

1. Conceptual Design

2. Physical Design

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continued4. The Star Life Cycle continued

Conceptual Design tells what is required, i.e. what the system should do, what the users need to know, etc.

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continued4. The Star Life Cycle continued

Physical Design tells how things that are required can be achieved.

The conceptual/physical distinction contributes to designing good systems because it leaves a lot of room for modification while the prototype design process has already started.

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continued4. The Star Life Cycle continued

Deferring decisions as to who or what will perform which functions to a later stage of the design process is particularly important in highly dynamic (=rapidly changing) fields such as IT. If there are rapid technology changes, this will have a strong impact on the outcome of the final design, because the changes also determine what design the user desires.

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continued4. The Star Life Cycle continued

This may get clearer with the following example:

Several years ago hardly any mobile phone had the option to send and receive SMS (text messages). Nowadays, it would be hard to sell a phone without this option.

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continued4. The Star Life Cycle continued

User Interface design before SMS was made possible needed to remain open for a sudden change in user demands, because once SMS became available, it became highly popular and most users wanted to have this option.

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continued4. The Star Life Cycle continued

In more classical models such as the Waterfall model, it would be more difficult to adjust to these rapid changes in user demands.

The Star Life Cycle therefore tries to meet these demands in a flexible way.

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continued4. The Star Life Cycle continued

In summary, the Star Life Cycle stresses on rapid prototyping, alternating waves of analytic and well-structured (top-down) and flexible (bottom-up) approaches.

It also stresses on realistic and user-centred evaluation.

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continued4. The Star Life Cycle continued

Because development of an interface design can begin from any point in the star (see slide with the figure), many limitations of traditional models such as the Waterfall and traditional Life Cycle Model can be overcome.

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continued4. The Star Life Cycle continued

Whilst the Star Life Cycle makes heavy use of prototypes, these are not the only models in the process of developing the interface, e.g. sketches, scenarios or formal notations are also applied and it very much depends on the context where they will be most effective.