User-Centered Design
Contents |
Abstract
As technology and services advance and become more deeply integrated in the daily live of their customers and therefore human lives, the different development processes and projects need to ensure that the offered solutions become more intuitive and user-friendly in order to secure customer satisfaction and stable sales. While taking a closer look on classical development models e.g. Waterfall model, it is clear that during the different project stages the focus of the project managers are only project related and mostly not viewed from an end customer perspective, which can cause usage and understanding problems[1].
The User-Centered Design Approach takes these problems into consideration. The goal is to design understandable and enjoyable solutions for the end customers, while either taking their personal opinions into account or lead the project from an end customer optimized view. Therefore the different processes must be lead towards a user's needs, abilities and expectations in order to guarantee a maximized customer focus. The UCD process consists of five steps, of which the last 4 are following a interative logic. Furthermore, the UCD is defined in the DIN EN ISO 9241-210 "Human-centred design for interactive systems " standard[2].
Characteristics & Principles
The UCD concept was first mentioned by Donald Norman in his publication "User-Centered System Design: New Perspectives on Human-Computer Interaction" in 1986 and further discussed in his book "The Design of Everyday Things". Norman shows the importance of a users need in a product and the mistakes caused by unappropriate designs, which aren't user focused and don't take these into account. Therefore he gives recommendations based on the users needs and wishes.
In order to reach a high level of usability the following principles must be followed as defined by Gould and Lewis in 1985.
- Iterative proceeding
- Early focus on user and task requirements
- empirical review of the designs by users
User-Centered Design Process
Having a closer look at classic development models shows that the focus of development does not respect the needs of the end users. As technologies advance and become more deeply integrated into human lifes, products or services must become more intuitive and user-friendly. Therefore, the goal is to design easy-to-learn and easy-to-use interactive products that provide the user with an optimal interface and an enjoyable user experience. For this, the development process must be geared towards the users and their needs, abilities and expectations must be taken into account. These criteria are fulfilled by the User Centered Design approach. Through the usage of the UCD developments of a wide range of products and services are conceivable. Principles of the approach are an iterative proceeding, an early focus on user and organizational requirements and the empirical verification of users' designs. The UCD process is presented in the standard DIN EN ISO 9241-210: 2011 " Human-centred design for interactive systems." Since the development of a human-friendly product is in the foreground, the term "human-centered design" is used. The procedure with five distinct phases essentially characterizes the process, whose phases are shown in Figure 1.
The user-centered design (UCD) design process for interactive systems according to ISO consists of five steps, of which the steps two through five are iterative. Since UCD can also be used to manage projects besides the development of interactive systems, the five phases according to ISO can be used by project managers of every kind. The following is a detailed description of the procedure.
Step 1: Identify need for human-centered design
UCD activities should play a central role as a guiding principle in all areas of project or product development. An involvement of all project members is important in order to avoid conflicts and to achieve an integration into all previous processes. A first meeting of all persons involved in the development represents the start of the UCD process. During this meeting general questions about the use of the product or the service should be answered.
Step 2: Understand and specify the context of use
The understanding and definition of the context of use is a central point in the UCD. Collecting information about the future users, their wishes and needs must be essential. In order to get to know the potential users, the use of an audience analysis is conceivable. This should result in a concrete distinction between different target groups from the mass of all users. Attributes help in the division into different groups. These may be demographic characteristics, such as age or gender, socioeconomic as well as education and occupation and psychological characteristics and attitudes and values. The data can be used as a first source for creating personas. The execution of a task analysis is conceivable as the next step. Here, the tasks that are important for the achievement of the objectives are broken down into small sub-steps and the sequence of orders and their execution conditions are analyzed. In this case, the result may represent, for example, in a hierarchy of goals up to the smallest steps required to solve the request. For example, Figure 2 shows a task analysis for installing an app on a smartphone. Last but not least, the analysis of the work or application environment may be an option. Many systems are exposed to very different environmental conditions, e.g. large temperature differences. In the environmental analysis, it is important to record all significant environmental influences, thus a system can be designed that works flawlessly under all expected environmental influences.
Step 3: Specify the user and organizational requirements
The determination of the usage requirements and thus the development of requirements for the use of the product or the service refer to the requirements of the users including the usage context defined in the previous step. In terms of content, these refer to the requirements of the users and thus exceed the descriptions of purely functional aspects. Realistic use cases help to integrate the personas into lifelike user experiences, whereby the involvement of personas in them realistically describes how to perform a specific task and what motivates the user to perform a task.
Step 4: Produce design solutions
Following the elaboration of the context of use and the user requirements, first solutions of the future product will be developed during this step. These are realized in different prototypes for visualization but also for evaluation. At the beginning, cost-effective and low-effort prototypes are presented to the customer, such as paper prototypes or simple forms on a screen. Customer wishes can be implemented quickly and easily. As development progresses, the prototypes become more and more similar to the final product. Functionalities and structure of the product approach the final version and thus implement findings from previous versions.
Step 5: Evaluate designs against requirements
In order to optimally integrate the wishes and needs of the customers into the process, prototypes should be tested and evaluated by them early on. Evaluation in development is one of the key points of the UCD process. At the outset, it is conceivable to carry out an expert evaluation, whereby a trained expert, who as yet has had as little involvement as possible in the previous development steps, evaluates the system from the point of view of a persona and documents problems that occur in the design solutions. A controlled testing with people from the targeted user group represent the standard of development, Once the design solution meets all user requirements, the process is completed and the product or service is fully developed.
Analysis Tools
There are a lot of tools which can be used during a UCD project to optimize the outcomes and goals. All of them try to help the project team to slip into the role of an user and understand its needs and wishes regarding a product. In the following three important Tools are described, while still a lot of tools as scenarios, use cases etc. could be mentioned.
