Many companies rely on old fashion design approaches and methods for achieving ease-of-use. With this paper, describing the most contemporary design methods used in the industry, we will try to create awareness by explaining, grouping them listing their k

The State Of Art Design Methods study on Ease-Of-Use

Abstract

Many companies rely on old fashion design approaches and methods for achieving ease-of-use. With this paper, describing the most contemporary design methods used in the industry, we will try to create awareness by explaining, grouping them listing their key principles and showing them in use in an industrial case study. The outcome of the case study gives ideas at which stage of designing, which design methods are preferred and how they facilitate the process.

Keywords

ease-of-use, usability, design methods, user-centered-design, informal and structured design methods

Introduction

During the last decade ease-of-use became a major part of any system or product development. Fred Davis defines it as “the degree to which a person believes that using a particular system will be free of effort” (F.Davis, 1996). There are many researches suggesting different design methods for achieving better ease-of-use/usability. According to Steve Krug there are no bad usability techniques, there are only wrongly chosen ones (S. Krug, 2005). In Nokia, expert evaluation and remote online evaluation are the evaluation methods for identifying the best concept from usability point of view (V. Roto, H. Rantavuo, and K. Vaananen-Vainio-Mattila, 2009). IBM is relying on User Centered Design (UCD) approach to achieve it: “User-Centered Design is a method for designing ease of use into the total user experience in our products” (K. Vredenburg, 1999).

The purpose of this paper is to describe, review and reflect on the most recent design methods used for achieving ease-of-use. The key design methods will be shown in practise in an industrial product case study “Alice”.

The word “product” is used in this paper interchangeable with physical products, software or service.

Design Methods

Design method (DM) “can ... be any procedures, techniques, aids or ’tools’ for designing”[5]. This section will define the most recent and used DMs. For each a brief explanation will be given as well as some of its key principles.

User Centered Design (UCD)

User Centered Design is an approach to produce a products, that fulfill user’s wishes and expectations. This approach concentrates on users’ requirements, expectations and limitations to a product at each design stage. It follows 6 key principles:

Set business goals - Specify target market audience, potential users and competitors.
Understand users - Continuous involvement and commitment from the users is vital to the success. The users have to be well understood.
Assess competitiveness - An evaluation of the competitors product should be done at that stage and the outcome should be measured against the designed solution.
Design the total user experience - consider everything that the user encounters, e.g. packaging, installation, manuals, support, recycling, etc.
Evaluate designs - Designers are gathering regularly user feedback and incorporate it into next design iteration to produce a better design.
Manage by continual user observation - User feedback is a keystone in UCD. The user voice should be present all over the design process at any level, e.g. requirements elicitation, market changes feedback, competitors products feedback, etc

Focus Groups (FG)

FG are well planned group of people, participating in moderated discussion, which are asked about their perceptions, feelings, attitudes and ideas on a product or a service. A focus group could be used to assess users satisfaction with a product. FG follow 4 key principles:

Select participants - they should match the intended users of the product developed.
Prepare questions - The questions are important part, because their answers are direct product feedback.
Appoint moderator - The FG participant should stay on track and there should be contribution from all participants.
Keep notes - Everything ...

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Focus Groups (FG)

Select participants - they should match the intended users of the product developed.
Prepare questions - The questions are important part, because their answers are direct product feedback.
Appoint moderator - The FG participant should stay on track and there should be contribution from all participants.
Keep notes - Everything should be recorded and scripted.

Usability Testing

Usability test is an design evaluation method, which is performed with real product users and provides direct feedback on the ease-of-use of a product or a system. It involves writing realistic scenarios and asking users to execute them while designers observe and record them. It can be facilitated by other methods like mock ups, prototypes, questionnaires, etc.

Cognitive Walk-through

Cognitive walk-trough is a design method for evaluating how easy it is for a new user to perform certain task with a product. The user is given a task and while he/she is going through it designer is capturing the output, e.g. achieving right effect, choosing correct action, how much time does it take. The output from Cognitive walk-through is input for the next iteration of design activity.

Prototyping

Prototype is a realization of a design concept. Prototypes are created in an early stage of development in order to allow test of a product before it actual manufacture. A prototype can be anything from a mock-up drawing to a 3D print of your product.

Use Cases

Use case is a scenario in which users will perform certain tasks with a system and the system will provide certain set of outputs depending on its prerequisite state. A use case includes brief successful scenario explanation, actors, prerequisites and the inputs and corresponding outputs. They are very helpful to elicit requirements, but also for designers to understand the system’s input and outputs.

Parallel design

Parallel design is a design method, which facilitates several designer working separately with the same set or requirements and aiming to create an initial product design. Later the designs are shared among the designers and each designer is trying to incorporate the best ideas from the others into his own design or further develop someone else solution.

This method helps to generate different ideas and ensures that the best ones are integrated into the final concept.

Contextual interview

Contextual interview is observing selected target users in their environment often in their home, social place or workspace. The observer is trying to understand how they feel and use the product sometimes by interrupting for short clarification questions. The 3 principles are:

Context - The interviews and observation of users in their environment during their ongoing work are vital for this method.
Partnership - The interviewer is not aware of interviewee’s work and is there to capture users experience.
Focus - The interview should do one task at the time that is the intended product task.

Personas

A persona is a fictional person, who represents goals and behavior of a real group of users. The persona has the characteristics that are most important for those groups.

Analyze interviews with users.
Defining personas.
Select main persona.
Design for that personas.

Scenarios

Scenarios are pre-planned stories targeting specific user, who is supposed to perform certain action and achieve certain goal with a product. Scenarios are also used by designers to design product based on predefined common goals and actions performed by target product users.

Design methods commonalities

In this section we will search for commonalities between DMs. Both structured and informal DMs will be used. The diagram below illustrates those common attributes and relationships.

Scenario based DMs

As the name suggests, these DMs are mainly making use of scenarios. They use the scenarios as a task, either to test the target user, or that designers should follow when designing.

Persona based DMs

These DMs are grouping the target users according to different parameters like sex, gender, age, location, etc. to be used later as a test group for different task, scenarios or discussion.

Other DMs

DMs belonging to that group are quite different than the others and are not making use of any common attributes.

Case Study “Allice”

This case study illustrates how some of the DMs, this paper is reviewing, have been used successfully to release the product Alice, developed for company Bob. Bob is a worldwide leading company on the GPS car navigation systems market famous for its high ease-of-use products.

The company has developed new generation GPS navigation, called Alice, which allows users to operate on totally new capacity touch screen device, making use of a new webkit based User Interface (UI), buy and upgrade maps and subscription services over new interface. Alice is an example how a company can redesign all its services, platform, hardware and software at the same time, driven by UCD. The case study Alice was conducted in the User eXperiecen (UX) department of Bob for sixteen months.

Project started with writing Use Cases (UC) in the UX department. The input for the UC was customer support feedback, Sr visual designers propositions and marketing researches. At that stage UC were used mainly as requirements elicitation tool, but later also facilitated the designers to understand the user flows in the system and the screens to be designed.

The next step was to develop new look and feel design. The task was done using parallel design method. The in-house design team and a design agency were given the requirements and were asked to produce new generation UI for Alice. In four weeks the complete design concepts were presented to the board of directors of Bob. After reviewing them only two were left, one from the in-house team and one from the agency. The teams were asked to swap their concepts and try to incorporate their ideas into the other team’s design.

The third step was to prototype the UI using Adobe Flash. The most common scenarios performed with the device UI were evaluated by an expert evaluation.

Prototyping was also used to incorporate the device’s hardware and software. That prototype helped the team to find serious design defects with both hardware and software such as capacity screen defect, touch event handling errors, visibility of the screen when mounted in a car and sun reflection causing mirror effect.

Fourth step was to perform cognitive walk-through with 20 end-users new to Alice. The users were asked to come to the UX laboratory and perform 10 most common tasks on Alice. A couple of usability experts were observing them and analyzing how long does it take to take for them to take a decision, to perform a task, etc. and were keeping notes. The outcome was a set of changes in the interaction design and task completion flow had to reduce number of clicks.

During next step a focus group was formed to facilitate the usability and UI implementation feasibility. The group consisted of the main designer, main front-end developer, back-end architect, requirements engineer, interaction designer and project manager. Some were providing usability information and others were evaluating if it is feasible.

The last step was a beta test, making use of conceptual interviews. End-users were asked to take an Alice device in their own car and perform the same 10 most common tasks. Example tasks were navigate to an address, check the traffic on route, prepare a route for future use, etc. While they were performing them an usability expert was asking clarification questions and keeping notes of common mistakes and difficulties.

Results

In the case study, presented in this paper, there was balance between informal and formal/structured design methods during all project phases. Another case study argues that “ informal and less structured methods tend to be used much more widely than more formal and structured methods. For example, ranked on top are informal usability testing, low-fidelity prototyping, and heuristics, whereas more formal methods are ranked at the bottom such as focus groups, cognitive walk-through” (K. Vredenburg, J. Mao, P. W. Smith, T. Carey, 2002).

Conclusion

This paper presented the most contemporary design methods to achieve better ease-of-use. They were briefly described and grouped according to common attributes they make use of. An industrial case study was used to demonstrate how these DMs were used to build a product, owning couple of best usability awards. The results from the case study presented a balance between informal and structured DMs usage. It also demonstrated a balance between persona based, scenario based and other DMs techniques.

References

F.D.Davis (1996) A model of the Antecedent of Perceived Ease of Use: Development and test, Decision Sciences, Vol. 32, No. 4, pp. 699-719
H. Beyer, K. Holtzblatt (1998) Contextual Design: Defining Customer-Centered Systems, Morgan Kaufmann Publishers
ISO 9241-210 (2008). Ergonomics of human system interaction - Part 210: Human-centred design for interactive systems (formerly known as 13407). International Organization for Standardization (ISO). Switzerland.
K. Vredenburg (1999). Increasing ease of use. Commun. ACM 42, 5 (May 1999), 67-71
K. Holtzblatt, J. B. Wendell, S. Wood (2005) Rapid Contextual Design, by Morgan Kaufmann Publishers
K. Vredenburg, J. Mao, P. W. Smith, T. Carey (2002) A survey of user-centered design practice. InProceedings of the SIGCHI conference on Human factors in computing systems: Changing our world, changing ourselves (CHI '02). ACM, New York, NY, USA, 471-478
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S. Krug (2005) Don’t Make Me Think!: A Common Sense Approach to Web Usability (Second Edition), New Riders
V. Roto, H. Rantavuo, and K. Vaananen-Vainio-Mattila (2009) Evaluating user experience of early product concepts, Designing Pleasurable Products and Interfaces, 13-16 October 2009, Compiegne, France