Week 8- by Tang Yook Meng

WHAT ARE REQUIREMENTS?

TO IDENTIFYING THE NEEDS & REQUIREMENT

• Is a statement about an intended product that specifies what it should do or how it should perform.
• Should be as specific, unambiguous and clear as possible
• Example: time to download any complete web page is less than 5 seconds VS teenage girls should find the site appealing
• Must know how to tell when they have been fulfilled

TYPE OF REQUIREMENTS

1. IN SOFTWARE ENGINEERING

• Functional requirements

WHAT the system should do? For examples, Word processor.

It should support a variety of formatting styles, and also formatting by paragraphs, character and etc.

• Non-functional requirements

WHAT are the constrains there are on the system and its development? For examples, Word processor.

It must be able to run on target platform such as PCs, Macs and Unix machines OR target platform must be have at least 1.0 GB RAM.

2. IN INTERACTION DESIGN

• Functional requirement

It capture what the product should do

• Data Requirements

Capture the type, volatility, size, amount, persistence, accuracy and value of the required data. Such as: Share-dealing application- data must be up to date, accurate and change many times a day.

• Environmental requirements/context of use

The circumstances in which the interactive product will be expected to operate. There are 4 characteristics: Physical environment is about how much light, noise and dust is expected in the operation environment. Social environment is a social aspect for interaction design to collaboration and coordination. Next, Organisational environment is how good is the user support likely to be, how easily it can be obtained, and are there facilities for training. Finally, technical environmental is about what technologies will the product run on or need to be compatible with and what technologies limitations might be relevant.

• User characteristics

Capture the key attributes of the intended user group. It means the user’s abilities and skills, user’s nationality, educational, background, preferences, personal circumstances, physical or mental disabilities. The collection of the attributes for a ‘typical user’ is called a user profile. Any one product may have a number of different user profiles, to bring user profile to file, they are turned into a number of Personas, which means rich descriptions of typical users of the product under development that the designers can focus on and design the product for. They don’t describe real people, but are synthesized from a number of real users who have involved in data gathering exercised.

• Usability goals and user experience goals

Usability goals are about effectiveness, efficiency, safety, utility, learnability and tracking. These all will form User’s Performance. While, user experience goals will form User’s Perception by having fun, enjoyable, pleasurable, aesthetically pleasing and motivating.

CONTEXTUAL INQUIRY

The designer works as an apprentice to the user in 4 principles:

• Context – Emphasize on going to workplace and seeing what happens.
• Partnership – Developer and user should collaborate in understanding the work.
• Interpretation – Observations must be interpreted in order to be user in design and the interpretation should be in cooperation between user and developer.
• Focus – Keeping the data gathering focused on your goals.

SCENARIOS

• It is an ' informal narrative description'.
• Describe human activities such as exploration and discussion of context, needs and requirement.
• Do not explicitly describe use of software or other technological support to achieve tack.
• Easy for stakeholders to relate.

USE CASES

• Emphasis on user-system interaction rather than the user's task itself and it’’s from the user’s perspective, not the system’s.
• User called an ‘actor’.
• Mainly use case describes normal course or sets of actions that is commonly performed.
• It can be described graphically by using case diagram.

ESSENTIAL USE CASES

• Developed to combat the limitations of scenarios and use cases
• It represents abstractions from scenarios and try to avoid the assumptions of a traditional use case.

TASK ANALYSIS

• Used mainly to investigate an existing situation, not to envision new products
• Analyse the underlying rationale and purpose of what people doing