Usability inspection

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Usability inspection is the name of a set of methods that an evaluator inspects a user interface. This is in contrast to usability testing on the usability of the interface is evaluated by the tests on real users. Usability Inspections usually in the early stages of the development method by evaluating prototypes or specifications for the method can not be tested on users. The usability inspection methods are generally thought about cheaper to implement than check users.
The usability inspection methods are:
• Cognitive Walk through
• Heuristic evaluation
• Tutorial pluralistic

Cognitive walk through:
The cognitive walk through method is a usability inspection method for identifying usability problems in a piece of application or website, focusing on how easy it is for new users to perform tasks with the method. The method is rooted in the notion that users generally prefer to learn a method by using it to accomplish tasks, than by example, the study of a manual. The method is valued for its ability to generate results quickly with low cost, Compared to usability testing and the ability to apply the method in the design before encoding even begun.

A tutorial begins with a cognitive task analysis that specifies the sequence of steps or measures required by the user to perform a task, and system responses to those actions. Designers and developers of software and steps tutorial as a group, ask a few questions at every step. Data are collected in the
tutorial, and after a report of potential issues is compiled. Finally, the software has been redesigned to address the issues identified.
The effectiveness of cognitive methods such as tutorials is difficult to measure in terms of value, since it is very limited opportunities for controlled experiments, while the software development. Normally the measurements of participation comparing the number of usability problems found by applying different methods. However, Gray & Salzman calls questioned the validity of studies in his dramatic role 1998 "Damaged Merchandise", demonstrating how
very difficult to measure the effectiveness of usability inspection methods. However, the consensus usability community is that the cognitive walk through method works well in a variety of environments and applications.

Walking through the tasks:
After the task analysis has been done to make the tutorial participants asking themselves a set of questions for each sub task. Usually they are asked three questions:
• Is the user trying to accomplish the effect that the sub task has? "You understand that this sub task is necessary to accomplish the objective of the user?
• Will the user notice the correct action is not obtainable? For example, the button visible?
• Are You understand that the desired sub task can be accomplished by the action? For example, the right button is visible, but the user does not understand the text and therefore not click it.
• Is the user receives feedback? Does the user know that have done the right thing after doing the action?By answering the questions for each sub task usability problems will be noted.

Heuristic evaluation:
A heuristic evaluation is a process of discounting the application control utility that helps identify usability problems in user interface (UI) design. Evaluators are supposed to look specifically at the interface & judge its compliance with recognized usability principles (the "heuristics"). These methods of assessment are now are taught & practiced in the field of new media, which are often designed user interfaces in a short space of time in a budget that may restrict the amount of money available to establish other types of interface testing.

The main aim of the heuristic evaluation is to identify issues associated with designing user interfaces.Usability consultant Jakob Nielsen developed this process based on several years of teaching experience and consultation on usability engineering.Heuristic evaluations are one of the more informal methods [1] Usability inspection in the field of human-computer interaction. There's lots of sets of usability design heuristics are not mutually exclusive and cover lots of of the same aspects of interface design.often, usability problems that are discovered are often classified on a numerical scale according to their
estimated impact on user performance or acceptance. Often the heuristic evaluation is conducted in the context of use cases (typical user tasks), to provide information to developers to the extent that the interface is likely to be compatible with the needs of intended users and preferences.The simplicity of the heuristic evaluation is beneficial in the early stages of design. This process of usability inspection does not need user testing can be daunting, due to the need of users, a place to check them and a payment of for your time. Heuristic evaluation requires only one expert, reducing the complexity and time taken to
assessment. Most heuristic evaluations can be accomplished in days. The time necessary varies with the tool size, complexity, the purpose of review, the nature of the usability problems that arise in the review, and the competence of the evaluators. Using the heuristic evaluation prior to user testing will reduce the number and severity of design errors discovered by users. Although assessment of usability heuristics can discover lots of of the major issues in a short period of time, a criticism often leveled is that the results are highly influenced by knowledge expert reviewer (s). This "unilateral" reviewed on several occasions has had different results from performance tests, each type of Check the discovery of a different set of problems.

Nielsen's heuristics:
Jakob Nielsen Heuristics are probably the most used usability heuristics for user interface design. Nielsen developed heuristics based on the work, together with Rolf Molich in 1990. [1] [2] The final set of heuristics that are still used were released today by Nielsen in 1994. [3] The heuristic that is published in Nielsen's book Usability Engineering are the follows
Visibility of process status:
The process should always keep users informed about what is happening, through appropriate feedback within
reasonable time.
Match between process and the real world:
The process should speak the user's language, with words, phrases and concepts familiar to the user, than
system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
User control and freedom:
Users often pick process functions by mistake and will need a clearly marked "emergency exit" to exit
Unwanted state without having to go through an extended dialogue. Support undo and redo.
Consistency and standards:
Users should not must wonder whether different words, situations, or actions mean the same thing. Follow conventions of the platform.
Prevention of error:
Even better than nice error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error or check the conditions set for them and users with a confirmation option before they commit to action.
Recognition than recall:
Minimize user memory load by making objects, actions and options visible. The user should not must recall information from four part of the dialogue to another. Instructions for use of the technique should be visible or easily retrievable whenever appropriate.
Flexibility and efficiency of use:
Accelerators - unseen by the novice user - may often speed up the interaction for the expert user such that the technique can satisfy both novice users and experienced. Permit users to tailor frequent actions.
Aesthetic and minimalist design:
Dialogues should not contain information that is irrelevant or seldom needed. Each additional unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
Help users recognize, diagnose, and recover from errors:
Error messages should be expressed in plain language (no codes), precisely indicate the problem, and suggest a constructive solution.
Help and documentation:
Although it is better if the technique can be used without documentation, it may be necessary to provide help and documentation. This information should be easy to search, focused on the user's task, list concrete steps that completed, and not giant.

Gerhardt-Powals’ cognitive engineering principles:
Although Nielsen is thought about the expert and leader in the field of heuristics, Jill Gerhardt-Powals also developed a set of cognitive principles to improve performance. These heuristics, or principles, are similar to those of Nielsen heuristic, but adopt a more holistic evaluation. From, Gerhardt Powals principles "are listed below.
• Automation of the unwanted workload:
• free up resources for high-level cognitive tasks.
• eliminate mental calculations, estimations, comparisons, and unnecessary thinking.
• Reducing uncertainty:
• display information in a way that is clear and obvious.
• Information from Fuse:
• reduce the cognitive load, collecting information at less than the sum of the higher level.
• Present new information with meaningful aids to interpretation:
• Use a familiar framework, making it easier to absorb.
• Using everyday terms, metaphors, etc.
• Use names that are conceptually related to function:
• context dependent.
• Trying to improve the recall and recognition.
• The group's information consistently significant to reduce the search .
• Limit data-driven tasks:
• Reduce the time of assimilation of raw information.
• Make appropriate use of color and graphics.
• Include in the sample only the information needed by the user at any given time.
• Provide multiple coding of information where applicable.
• Practice wise redundancy.

Pluralistic walk through:
The pluralistic walk through (also called study participatory design, user centered Tutorial,Storyboard, Table-Topping, or Tutorial Group) is a usability inspection method to identify usability questions on a piece of program or web-site in an work to generate a maximum usable man-machine interface. The
method centers around the use of a group of users, developers and usability professionals to pass through a stage of work,discuss usability issues related to elements involved in the dialogue of the stage steps. The expert group used Are invited to assume the role of the typical users of the check. The method is valued for its ability to be used in the earliest stages of design, allowing the resolution of usability problems quickly and early in the design method. The method It also allows the detection of a greater number of usability problems found in a moment due to the interaction Multiple types of participants (users, developers and usability professionals). This type of usability inspection method has the additional aim of increasing sensitivity to the concerns of developers to users on product design.


Walkthrough Team:
A tutorial team must be assembled before the pluralistic walkthrough. Two types of participants are included in the tutorial: representative users, product developers and human factors (the utility), engineers and professionals.Users should be representative of the target audience, and are thought about the major participants in the usability assessment. A product developers answer questions about the design of suggesting solutions to problems users have
found. Human factors professionals often serve as facilitators and are also there to provide information on design and recommend design improvements. The facilitator's role is to guide users through tasks and facilitate collaboration between users and developers. It is best to keep away from a product developer to assume the role of facilitator, as they may become defensive to criticism of its product.

The following materials are necessary to over out a tour plural:
• Living sizable to accommodate approximately 6-10 users, 6-10 developers & 2-3 usability engineers
• Screen Printed shots (paper prototypes) packaged together in the same order as the screens when users were performing specific tasks. This includes a copy of the display panels, dialog boxes, menus, etc. presented in order.
• Hard copy of the scenarios for each participant. There's several scenarios described in this document complete with the information to be manipulated for the task. Each participant will get a package that allows him or her to write a response (ie the action to take on that panel) directly on the page. Job descriptions for the participant are brief direct exposure.
• Writing utensils to make screenshots & documentation & fill out questionnaires.Participants get written instructions & rules at the beginning of the tutorial session. The rules indicate that all participants (users, designers, usability engineers) to:
• Assume the role of users
• To write in the panels of the measures to take in achieving the task at hand
• To enter any additional comments about the task
• Do not fold forward to other groups until they are told that
• To keep the discussion on each panel until the moderator decides to go ahead.

Tutorials are pluralistic group activities that need the following steps should be followed:
1. Participants are presented with instructions and the basic rules above. The description of the task and package also distributed scenario.
2. Then, an expert in the product (usually a product developer) gives a brief description of the key concepts of the product and interface features. This overview serves the purpose of encouraging participants to visualize the finish product finish (application or web-site) so that participants acquire the same knowledge and expectations of the last product that finish users of the product that is supposed to have.
3. Usability testing then begins. The scenarios are presented to the panel and participants are asked to write the sequence of action to take in attempting to complete the specified task (ie, move from four screen to another). They do this individually, without conferring with each other.
4. When everyone has written their actions independently, participants discussed the actions that suggested for the task. They also discuss potential usability problems. The order of the communication is usually so that representative users first go to are not influenced by other group members and are not
discouraged from speaking.
5. After users have done, the usability experts present their conclusions to the group. Developers often report its rationale for its design. It is imperative that developers embrace an attitude of welcome comments are intended to improve the usability of your product.
6. The facilitator tutorial presents the correct answer, if the debate is off coursework and clear up any clear situations.
7. After each task, participants are given a short questionnaire on the usability of the interface have only evaluated.
8. Then the panel gets the next task and around the screens. This technique continues until all scenarios have been been evaluated.
Throughout this technique, the usability problems are identified and classified for future action. The presence of the different types of participants in the group allows a synergy potential for development that often leads to creativity and collaboration solutions. This allows a focus on user-centered point of view, while also taking in to account the engineering design limitations of practical systems.

Characteristics of Pluralistic Walk through:
Other usability inspection methods are: Cognitive tutorials, interviews, focus groups, remote Tests & think aloud protocol. Tutorials pluralistic shares a number of the same features with these other traditional tutorials, cognitive tutorials, but there's some characteristics that define(Nielsen, 1994):
• The main alter with respect to the tutorials usability should include four types of participants:representative users, product developers, & human factors (usability) professionals.
• Hard copy screens (panels) are presented in the same order they appear online. A working scenario is defined, & participants at the screens in a linear path through a series of user interface panels, as that for the successful completion of the task specified in line like the site / program is currently designed.
• Participants were asked to assume the role of users for any user population being tested. Thus, the developers & usability professionals are supposed to try to get in the place of users when provide written replies.
• The participants write down the measures to take in the search for the line of work designated, before continuing discussion is made. Participants must write their answers in as much detail as possible to the keystroke or other action level of entry. These written responses that there is some quantitative information on production user actions that may be of value.

Benefits and Limitations:
There are several advantages that make the pluralistic usability walkthrough a valuable tool.
• Early systematic look at a new product, obtaining early performance & satisfaction information from users about a product. It can provide early performance & satisfaction information before design strategies have been expensive practice.
• Strong focus on user-centered design in task analysis, which leads to more problems identified at an earlier point in the development. This reduces the check cycle iterative redesign through the use of immediate feedback & discussion of design problems & possible solutions while users are present.
• Redesign synergistic because the group method for users, developers & usability engineers. The discussion of the problems identified in a multidisciplinary team to generate creative & useful solutions & quick.
• Valuable quantitative & qualitative information is generated by user actions documented by the written answers.
• Product development in the period of recognition of gain to users' common problems, frustrations or concerns regarding product design. The developers are becoming more sensitive to the concerns of users.

There are several limitations to the pluralistic usability walkthrough that affect their use.
• The route can only progress as slowly as the slowest person in each panel. The tutorial is a group exercise and, therefore, to discuss a task / screen as a group, they expect that all participants have
written answers to the situation. The session can feel laborious if it is slow.
• A gigantic group of users, developers and usability experts must be put in the same time. Programming could be a problem.
• All possible actions can not be simulated in printed form. Only one viable path shown interest stage.This prevents participants from navigation and exploration, the behaviors that often lead to further learning about user interface.
• Product developers do not feel comfortable listening to criticism about their designs.
• Only a limited number of scenarios (ie, paths through the interface) can be explored due to time constraints.
• Only a limited number of recommendations can be discussed due to time constraints.

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