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Design Process. Obstacles in development path. No body ever gets it right for the first time. Development is chock full of surprises. Good design requires living in a sea of changes. Designers need good tools. Performance design goals.
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Obstacles in development path • No body ever gets it right for the first time. • Development is chock full of surprises. • Good design requires living in a sea of changes. • Designers need good tools. • Performance design goals. • People may make mistakes while using a good system also.
Pitfalls or difficulties in development path • No early analysis and understanding the users needs and expectations. • A focus on using design features or components. • No usability testing. • No common design team vision. • Poor communication.
HUMAN INTERACTION WITH COMPUTERS Why People Have Trouble with Computers • Use of jargon (difficult in language spoken by language) • Non-obvious design(Complex) • Fine distinctions or dissimilarities(an action can be performed in multiple ways which yields similar results). • Disparity or inconsistency in problem-solving strategies(trial and error method it may lead to infinite so we will restart) • Design inconsistency (different information processing systems process same actions but are named differently on different consoles). Ex: shutdown or turn off
Psychological User Responses to Poor Design The psychological responses affects the users concentration to design an efficient model, thus resulting in higher error rates, low- performance, and dissatisfaction to the user. • Confusion • Irritation or Annoyance • Frustration • Fear of terror or stress • Boring
Physical User Responses to Poor Design • Abandonment or rejection of the system • Limited or Partial use of the system • Indirect use of the system • Modification of the task • Compensatory activity • Misuse of the system • Direct programming
Important of Human Characteristics in Design • Perception • Memory • Visual acuity • Foveal and peripheral vision • Sensory storage • Information processing • Learning, skill • Individual differences.
Perception • Perception is our awareness and understanding of the elements and objects of an environment • Perceptual characteristics include the following: • Proximity or closeness • Similarity or resemblance • Matching patterns • Succinctness or compactness • Closure • Unity • Continuity • Balance • Expectancies • Context • Signals versus noise
Memory Memory consists of mainly two components • Short-term • Long-term Visual Acuity The capacity of the eye to resolve details is called visual acuity. Peripheral and foveal vision • A vision which is utilized to directly focus on something is called foveal vision. • A vision which senses anything in its surroundings is called peripheral vision.
Sensory Memory • Sensory memory acts as a buffer. • It automatically process information collected from stimuli. • Sensory storage acts as a radar which frequently scans the objects from the surrounding that are important and passes it on to higher memory. Information Processing • The information that is gathered by senses has to be processed in an appropriate way: • There are two levels of information • Higher-level (capacity is limited, slow and sequential) • Lower level(unlimited, processes quickly)
Learning process Skill • Applying skills that allows one situation to be used in another situation. • The ultimate goal of human is to perform skillfully which can be achieved by linking inputs and responses into a sequence of actions. Individual Differences
Human Considerations in Design The User’s Knowledge and Experience The designing of an interface in a better way depends on the user’s knowledge and experience. Following are the considerations about the user’s experience and knowledge
Application Experience • Have users worked with a similar application ? • Are they familiar with the basic application terms? • Or does little or no application experience exist? Educational level • What is the general educational level of users? • Do they generally have high school degrees, college degrees, or advanced degrees? Reading level • Reading Level Less than 5th grade, 5th–12th, more than 12th grade. Typing skills • Typing Skill Expert (135 WPM), skilled (90 WPM), good (55 WPM), average(40 WPM), or "hunt and peck" (10 WPM).
The User’s Tasks and Needs In system design, user’s tasks and needs are very important. Mandatory or optional User Characteristics of a Mandatory user • The computer is used as part of employment. • Time and effort in learning to use the computer are willingly invested. • High motivation is often used to overcome low usability characteristics. • The user may possess a technical background. • The job may consist of a single task or function. Characteristics of a optional user • Use of the computer or system is not absolutely necessary. • Technical details are of no interest. • Extra effort to use the system may not be invested. • High motivation to use the system may not be exhibited. • Voluntary use may have to be encouraged.
The User’s psychological characteristics The User’s Physical characteristics
Understand the Business Functions Basic Business functions Basic business functions gives an overview of how profit and non-profit organizations function and how the basic business principles are used in finding out the organization’s success. The general steps to be performed are: • Perform a business definition and requirements analysis. • Determine basic business functions. • Describe current activities through task analysis. • Develop a conceptual model of the system. • Establish design standards or style guides. • Establish system usability design goals. • Define training and documentation needs.
Requirement Analysis • The objective of requirement analysis is to establish system needs. • The following methods are used for determining requirements. • Direct Methods (direct method are advantageous as they provide opportunity • to a user to express own views and comments). • Indirect Methods (indirect method play the role of an intermediary between • the user and the developer).
Determining Basic Business Functions The process used by the developer for determining basic business functions are as follows • Gain a complete understanding of the user’s mental model based upon: • The user’s needs and the user’s profile. • A user task analysis. • Develop a conceptual model of the system based upon the user’s mental model. This includes: • Defining objects. • Developing metaphors( phrase is used to represent).
Understanding the User’s Mental Model An internal representation of user's or clients present concept and understanding of something is referred as “mental model”. • Performing a Task Analysis • Classification of objects according to the sorted format • Things that can be experienced by physical touch. (concrete objects). • Clients who are the object of sentences. (customers or employee of an organization) • Things that keep track of information periodically.(paper survey).
Developing Conceptual Models A framework that describes the relationships between objects, the properties of objects, how objects are represented by an interface are presented to a client through a conceptual model. Components of conceptual model are, • System input-outputs. • Actions • Feedback and guidance characteristics. A conceptual model includes, • Defining objects • Developing metaphor
Design Standards or Style Guides • A design standard is also known as “Style Guide”. A design standard gives genuine guidance on the usage of the system components • Allow faster performance. • Reduce errors. • Reduce training time. • Foster better system utilization. • Improve satisfaction. • Improve system acceptance. • They are valuable to system developers because they: • Increase visibility of the human-computer interface. • Simplify design. • Provide more programming and design aids, reducing programming time. • Reduce redundant effort. • Reduce training time. • Provide a benchmark for quality control testing.
Document Design • Include checklists to present principles and guidelines. • Provide a rationale (set of reasons) for why the particular guidelines should be used. • Provide a rationale describing the conditions under which various design alternatives are appropriate. • Include concrete examples of correct design. • Design the guideline document following recognized principles for good document design. • Provide good access mechanisms such as a thorough index, a table of contents, glossaries, and checklists.
System Training • Online help. • Online tutorial. • Manuals. • Fast reference guides.