Nov 4 - Jeffrey Rubin, The Problem of Unusable Products and Systems

Chapter 1
The Problem of Unusable Products and Systems


Five Reasons for Hard-To-Use Products and Systems

1. During product development, the emphasis and focus have been on the machine or system, not on the person who is the ultimate end user.

2. As technology has penetrated the mainstream consumer market, the target audience has changed and continues to change dramatcially. Development organizations have been slow to react to this evolution.

3. The design of usable product is a difficult, unpredictable endeavor, yet many organizations trust it as it were just "common sense."

4. Organizations employ very specialized teams and approached to product and system development, yet fail to integrate them with each other.

5. The design of the user interface and the technical implementation of the user interface are different activities, requiring very different skills. Today, the emphasis and the need are on the design aspect, while many engineers possess the mind set and skill set for technical implementation.

User-Centered Design - Definition

User-centered design (UCD) is the most recent term coined to describe an approach that has been around for decades under different names, such as human factors engineering, ergonomics, and more recently, usability engineering.

UCD represents not only the techniques, processes, methods and procedures for designing usable products and systems, but just as important, the philosophy that places the user at the center of the process.

Three Principles of A User-Centered Design
1. An early focus on users and tasks.
2, Empirical measurement of product usage.
3. Iterative design whereby a product is designed, modified, and tested repeatedly.

Product Development Life Cycle
(Figure 1.5)
1. User and Usage Needs Analysis.
2. Specification of Requirements.
3. Preliminary (High Level) Design.
4. Detailed Design.
5. Product Build.
6. Product Release.

Hewlett Packard's Human Factors During Life Cycle
(Figure 1.6)
HUMAN FACTORS ACTIVITIES
Phase 1 (Needs Analysis)
* Identify and charaterize target user population.
* Identify and analyze user tasks.
* Identify users' physical and organizational environment.
* Identify usability problems on similar or existing products.
* Identify users' product feature list.
Phase 2 (Requirements Specification)
* Identify ergonomic or market-based requirements.
* Define and develop product usability and acceptance goals.
* Define product localization plan.
* Develop usability testing schedule.
Phase 3 (Conceptual Design)
* Develop product interface requirements.
* Define mental models describing system from the users' perspectives.
* Determine allocation of functions between user and system.
* Integrate Human Factors data, principles and guidelines.
* Test conceptual models.
Phase 4 (Prototype, Development and Test)
* Provide technical support in the development of product prototypes.
* Review production prototypes for ergonomic compliance.
* Test usability of HW, SW, and Learning Products.
* Provide feedback (including design recommendations) for designers based on results of usability test.
Phase 5 (Product Evaluation)
* Review final product specifications to ensure agreed upon usability recommendations have been satisfactorily implemented into the product design.
* Conduct on-site customer evaluations to determine product usability and how the product effectively meets user needs and expectations.
* Provide Marketing with usability advantages of the product.

Usability Goals and Objectives

It is generally accepted that an operational definition of usability include one or more of the following four factors, as outlined by Booth [15].
1. Usefulness
2. Effectiveness (ease of use)
3. Learnability
4. Attitude (likability).

Usability Testing

Usability testing is roughly divided into two main approaches.
The first approach involves formal tests conducted as true experiments, in order to confirm or refute specific hypotheses.
The second approach, a less formal one, employs an iterative cycle of tests intended to expose usability defieiencies and gradually shape or mold the product in question.

Usability testing divided into four types of tests.
1. Exploratory
2. Assessment
3. Validation
4. Comparison.


Source:
Jeffrey RUBIN. Handbook of Usability Testing: How To Plan, Design and Conduct Effective Tests. John Wiley & Sons, New York. 1994.