Conceptual Models: needs & requirements (deadline: 09/13/2016 12:30)

All the three reading materials are about one of the most important principles of design, which is easy to be neglected by engineers. However, talking about it as a customers, whether a designs have lots of functions are not as important. The only thing important for me is what kinds of functions that I can utilize. After reading these materials, something changed in my mind.

(The three materials I mentioned are :
Terry Winograd, The Alto and the Star, in Winograd, T., Gordon, P., eds, Bringing Design to Software, New York: Pearson, 1996.
David Liddle, Design of the Conceptual Model, in Winograd, T., Gordon, P., eds, Bringing Design to Software, New York: Pearson, 1996.
Yvonne Rogers, Helen Sharp, Jenny Preece (RSP), Interaction Design: Beyond Human-Computer Interaction, 3rd ed, Wiley. 2007, Chapter 10, Identifying needs and establishing requirements.)

First of all, as an influential operating system, the Xerox Star which is designed by PARC and utilized by the Alto PC, has a really user-friendly interface, which is shown below. And the Xerox Alto is the first computer that are graphical user interface(GUI). The computer and the system are so successful that it is not out-dated even discussed in modern society, which means designers still adopt some part of their designing even today. Why is the PARC so successful? According to the material, The Alto and The Star, it was because the PARC company adopted three main design of principles that the Xerox Star became so communicative design. (The three main principles are direct manipulate, WYSIWYG and consistency of commands. Since the three principles are so important, I list them below.)

The Xerox Star 8010 interface
1. Direct manipulation. The core concept that distinguished Star (and other Alto programs) from the conventional computer interfaces of their time was the use of a bitmapped screen to present the user with direct visual representations of objects.
2.WYSIWYG (what you see is what you get). Alto programs pioneered a new style that Star unified, in which the user works directly with the desired form, through direct manipulation.
3. Consistency of commands. Because all Star applications were developed in a unified way by a single development group, it was possible to adhere to a coherent and consistent design language. The Open command was the basis for applying a technique of progressive disclosure — showing the user only the relevant information for a task at hand, and then providing a way to reveal more possibilities as they were needed.

On top of that, the interview, which is recorded in the Design of the Conceptual Model, shows us the processes and the train of thought of the design. Based on the thought of IBM which is individual computers, Xerox fostered the ideas to develop the Star and the Alto. They did research at the beginning, which lead to a basic platform, the prototype of the 8010 Star. The process that they develop their products is a circle of figuring possible screen, design the prototype, testing with users and specifying for that new designs. Before the last version of the product coming to our views, this circle has been go through dozens of times. Although adding a process of testing with users increase lots of difficulties to designing a product, but in my opinion, the most creative part is also this processing. Before the Star and the Alto, designers were always focused on the constrains of the tech and their own thoughts, but PARC was focused on the customers. As I said, the most important thing of a product is what kinds of functions can be used by us, so it is the creative process that lead to the success of PARC. Also, the success of the Star has some part of the results of the success of the hardware of the Alto. Since the hardware gives enough spaces for developing according to David Liddle. And the three changes according to him is also deserved to think. But in my opinion since people care more about their preferences rather than prices and practicabilities, the difficulties of using new techniques and the focuses on the financial aims are not strange. Anyway, the changes of the principle of new techniques are not disobey the core principle that software designs must base on the user’s experience.

Eventually, what materials I learn most is the third part which is Identifying needs and establishing requirements. When people want to design an interface, they need to understand the users first and then produce. For understanding the users, people need requirement analysis/engineering, which is the process of gathering the data, analyzing the data and exacting the requirements. The requirement is a statement about an intended product that specifies what it should do or how it should perform. The principle of the requirement is specific, unambiguous and clear. It can be divided into functional requirements and the non-functional requirements. The non-functional requirements can also be divided into data requirements, environmental requirements (concerning circumstance, social environment ,organizational environment and technical environment) and the user characteristics. The functional requirements are the most important part of all requirements, which is satisfying the needs of users. The first step of requirement engineering is collecting data. Researchers need to collect sufficient, relevant and appropriate data through several ways: Interviews, Focus Groups, Questionnaires, Direct Observations, Indirect Observations, Studying Documents and Researching Similar Products. The choice of the methods depend on the nature of the task, the principles, the analyst and the resources available. Sometimes, people have to use several methods together to get their data. And to describe the business tasks, people can use business scenarios, use cases and essential use cases. Scenarios describe the human activities and tasks with the vocabularies and phrases of users; use cases describe the interaction between the software and the users in assumptions; the essential use cases are combines of both scenarios and use cases. To analysis a task, people can use HTA and GOMS. HTA is a method to break a task into subtasks and then break the subtasks into subtasks and so on.

To sum up, the first material introduces the Star and the Alto, which is based on the user’s experiences; while the second material specify the train of thoughts of the Star and the Alto, which is how to base on the user’s experiences; the third material is the specific methods to base the designs on user experiences. The three materials are a series to give us examples and to teach us to consider user’s experiences while designing. As a student of computer science, it is important for us to convey the most important part of the designs into our own designs. When I design softwares, I will remember that the most important thing is not what I think about the software or what I can do with the hardware, but is what users need and what may cause troubles of users. This three materials help me to focus on right things while design, so I will not design the most technological things but the most user-friendly things.