Evaluation of Software Interface
The evaluation of the software interfaces is one of the prominent concepts in Human Computer Interaction (HCI). In order to increase the usability, the design of software interfaces becomes an important task for HCI experts.
Introduction:
An effective source to exchange information and interaction between a user and a computer are software interfaces. Designing a software interface that is easy to use, easy to learn and easy to memorize are the attributes of the software usability evaluation. Therefore, the software evaluation is an important concept in the HCI. In designing the software interfaces, the SE and HCI need to understand the user behaviours, user familiarity with different features of the software interface and the user expertise while working with other software interfaces. The HCI deals with social, cognitive and interaction phenomena. Where the social layer focuses on how people interact with each other as well as with technology.
In the HCI, software evaluation plays an important role to achieve user goals in an effective, efficient and satisfying way. It is a discipline that helps to achieve usability during
the design of software interfaces. Software evaluation is the part that contains various techniques like heuristic evaluation, guideline reviews, cognitive walk through and usability testing.
Heuristic evaluation:
A heuristic evaluation is a usability inspection method for computer software that helps to identify usability problems in the user interface design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles. These evaluation methods are now widely taught and practiced in the new media sector, where UIs are often designed in a short space of time on a budget that may restrict the amount of money available to provide for other types of interface testing.
The main goal of heuristic evaluations is to identify any problems associated with the design of user interfaces.Heuristic evaluations are one of the most informal methods of usability inspection in the field of human-computer interaction. There are many sets of usability design heuristics they are not mutually exclusive and cover many of the same aspects of user interface design.
cognitive walk through:
The cognitive walkthrough method is a usability inspection method used to identify usability issues in interactive systems, focusing on how easy it is for new users to accomplish tasks with the system. Cognitive walkthrough is task-specific, whereas heuristic evaluation takes a holistic view to catch problems not caught by this and other usability inspection methods. The method is rooted in the notion that users typically prefer to learn a system by using it to accomplish tasks. The method is prized for its ability to generate results quickly with low cost, especially when compared to usability testing, as well as the ability to apply the method early in the design phases, before coding even begins.
A cognitive walkthrough starts with a task analysis that specifies the sequence of steps or actions required by a user to accomplish a task, and the system responses to those actions. The designers and developers of the software then walk through the steps as a group, asking themselves a set of questions at each step. Data is gathered during the walkthrough, and afterwards a report of potential issues is compiled. Finally the software is redesigned to address the issues identified.
Usability testing:
Usability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system.[1] This is in contrast with usability inspection methods where experts use different methods to evaluate a user interface without involving users.
Usability testing focuses on measuring a human-made product's capacity to meet its intended purpose. Examples of products that commonly benefit from usability testing are foods, consumer products, web sites or web applications, computer interfaces, documents, and devices. Usability testing measures the usability, or ease of use, of a specific object or set of objects, whereas general human-computer interaction studies attempt to formulate universal principles.
Main Principles in evaluation of Software Interface:
Purpose:
Is this the application I intended to run? Can I easily determine what the application is for?
Structure:
What is the interface layout? Can I find where everything is in the application window and how it all fits together?
Interaction:
Can I do what I ran the application to do (e.g. successfully type a document or configure a system setting)?
Navigation:
Was I made aware that the application launched? Can I get to everything in the interface? Can I get back to each application screen if I need to?
Keeping these four principle areas in mind will help you glean the purpose of a given accessibility requirement and will ensure that applications that pass your evaluations are usable by diverse user groups.
Evaluation criteria also includes:
End User Needs:
What does the user of the software want to do, what are their present skills and how do they intend to use the software? It is important to be very clear about the problem that is to be tackled by the software. For example, a disabled person who wants to write letters but cannot type might strongly consider software with lots of ready-made letter templates that can then be added to using voice recognition.
Functionality:
Does the software perform the functions required? Does it have specific facilities? For example, someone buying a spreadsheet application might need to produce graphs and charts.
Performance:
How well does the software work? This is normally available as benchmark test reports where independent tests have been carried out using the software.
Ease of use:
How easy is the software to use? Is there built-in help? It is important to be happy with the user interface.
Compatibility with existing data:
Will the new software be able to read any data that is already in use, ie in a different format or file type? If not, is it easy to convert existing files to a readable format?
Compatibility with existing hardware:
Software is written to run on a specific operating system, eg Windows, OSX (Macs) or Linux. It is sometimes written to run on and take advantage of specific hardware too. The new software needs to be compatible with the existing operating system and hardware.
Robustness:
How does the software handle problems? Robust software works well in combination with different hardware and software without crashing.
Cost:
Costs have to be weighed against the benefits that the software will bring. These may be about making more money or doing something quickly or with fewer staff hours involved. Price doesn't always dictate the best piece of software for the job, ie just because it's more expensive it doesn't necessarily means it's better.
Support:
The level of support when using the software can be crucial to making it a success or failure. Is a telephone or web based helpdesk available for the software? Are there any tutorials or training courses available?
Customisation:
Will the software allow users to change the look and feel so that it does exactly what they need? If so, is this easy to do?
Goals and results of evaluation
Software evaluation has pragmatically chosen goals. In the domain of software evaluation, the goal can be characterised by one or more of three simple questions:
1. “Which one is better?”
The evaluation aims to compare alternative software systems, e.g. to choose the best fitting software tool for given application, for a decision among several prototypes, or for comparing several versions of a software system.
2. “How good is it?”
This goal aims at the determination of the degree of desired qualities of a finished system. The evaluation of the system with respect to “Usability-Goals” [9, 94] is one of the application of this goal. Other examples are the certification of software, and the check on conformity with given standards.
3. “Why is it bad?”
The evaluation aims to determine the weaknesses of a software such that the result generates suggestions for further development. A typical instance of this procedure is a system developing approach using prototypes or a re-engineering of an existing system.
Key Points Related software Interface:
- User interfaces should be designed to match the skills, experience and expectations of its anticipated users.
- System users often judge a system by its interface rather than its functionality.
- A poorly designed interface can cause a user to make catastrophic errors.
- Poor user interface design is the reason why so many software systems are never used.
Human factors in interface design
Limited short-term memory
- People can instantaneously remember about 7 items of information. If you present more than this, they are more liable to make mistakes.
People make mistakes
- When people make mistakes and systems go wrong, inappropriate alarms and messages can increase stress and hence the likelihood of more mistakes.
People are different
- People have a wide range of physical capabilities.
- Designers should not just design for their own capabilities.
People have different interaction preferences
- Some like pictures, some like text.
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