Human-Computer Interaction 11. Evaluating User Interface (2) Dr. - - PowerPoint PPT Presentation
Human-Computer Interaction 11. Evaluating User Interface (2) Dr. Sunyoung Kim School of Communication & Information Rutgers university Quiz #3 Max: 20 Median: 17 Min: 4 5 3 3 3 2 2 2 2 1 0 0 0 0 0 0 0 20 19 18 17 16
School of Communication & Information Rutgers university
Max: 20 Median: 17 Min: 4
3 2 5 3 2 3 2 2 1 20 19 18 17 16 15 14 13 12 10 9 8 7 6 5 4
the middle, which means warm colors cannot be created with a cool color
spectrum, which means other cool colors are created by combining blue with a warm color
professionalism
§ Whether it’s any good? § Whether the interface (between a system and user) meets requirements and criteria? § Whether the users are able to complete all important tasks?
“The effectiveness, efficiency and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment.” (by ISO)
Satisfaction
What about…
final product
redesign”
User testing User testing User testing Paper sketches Wireframing Interactive prototyping Coding User testing
– Experts’ opinions, inspections, walkthroughs – How do experts think the users will perform on a system?
– User opinions – How do users think they will perform on a system?
A usability evaluation method in which one or more evaluators work through a series of tasks and ask a set of questions from the perspective of the user. The focus of the cognitive walkthrough is on understanding the system's learnability for new or infrequent users
a given system
than to read a manual or follow a set of instructions.
First, you need to define the tasks. And then, you need a complete, written list of actions needed to complete the task. E.g., Task: Create a customized voicemail message on an iPhone Actions 1. Tap Voicemail 2. Tap Greeting 3. Tap Custom 4. Tap Record and speak your greeting 5. When you finish, tap Stop 6. To listen to your greeting, tap Play 7. To re-record, repeat steps 4 and 5 8. Tap Save Sometimes defining the tasks is all you need to do to realize there is a problem with the interface.
(e.g., http://buenavista.typepad.com/buena_vista/2007/06/the_mobile_user.html)
The cognitive walkthrough is structured around 3 questions that you ask of every step (or action) in the task. You ask these questions before, during and after each step (or action) of the task. If you find a problem, you make a note and then move on to the next step of the task. 1. Visibility: Is the control for the action visible to the user? 2. Affordance: Is there a strong link between the control and the action? (Will the user notice that the correct action is available?) 3. Feedback: Is feedback appropriate? (Will the user properly interpret the system response?)
To find problems with hidden or obscured controls E.g. is the button visible? To find issues with context-sensitive menus or controls buried too deep within a navigation system. If the control for the action is non- standard or unintuitive then it will identify those as well.
Will the user notice that the correct action is available? To find problems with ambiguous or jargon terms, or with other controls that look like a better choice
Will the user properly interpret the system response? To find problems when feedback is missing, or easy to miss, or too brief, poorly worded, inappropriate or ambiguous. For example, does the system prompt users to take the next step in the task? Will the user know that they have done the right thing after performing the action? E.g. A control panel for an electronic toilet door on a British train: What button would you press if you want some privacy?
Task: Change a profile picture of my google account
Anyone can conduct a cognitive walkthrough; however, there is a risk that someone who is already familiar with your jargon, language and system is going to miss things that someone who lacks that familiarity would find. If you have to use someone who is very familiar with the product, make sure they have user personas to hand – to try and guide them to “walk a mile in the user’s shoes”.
You should record the step in the process where an assessor found an issue and what that issue was. When the process is complete, roundup all the assessors’ reports into a single report and then prioritize issues for fixing.
A principle or “a rule of thumb” which can be used to identify usability problems in interaction design: a researcher walks through a product and compare it to the heuristics and make their own assessment as to whether the product follows these rules of thumb
usability problems
1. High quality content 2. Often updated 3. Minimal download time 4. Ease of use 5. Relevant to users’ needs 6. Unique to the online medium 7. Net-centric corporate culture Heuristics are still needed for mobile devices, wearables, virtual worlds, etc.
1. Know what you will test and how: Before you begin any form of usability testing or user research it is essential for you to have an
2. Understand users: You also need some background on your users. This form of testing doesn’t involve users but your evaluators need to be able to act on behalf of the user 3. Briefing session to tell experts what to do. Provide experts with task descriptions 4. Evaluation period of 1-2 hours in which: – Each expert works separately – Take one pass to get a feel for the product – Take a second pass to focus on specific features 5. Debriefing session in which experts work together to prioritize problems
Keep users informed about what is going on. Example: response time
focused on action
bars
Users should always be aware of what is going on.
The elements and terms used in your system should match those used in the real world as closely as possible.
Users don’t like to be trapped! Strategies
undo, redo
actions easy to perform
exit" signs
can, without being annoying or
Be consistent and follow accepted industry standards in your site
Help users recover from an error by giving a precise description of what the error is, why it occurred, and possible solutions for recovering from the error.
Help users recover from an error by giving a precise description of what the error is, why it occurred, and possible solutions for recovering from the error.
Eliminate error-prone conditions or check for them and ask for confirmation.
Aid users with specifying correct input.
Minimize the user’s memory load by making objects, actions, and options visible.
Minimize the user’s memory load by making objects, actions, and options visible.
it comes to finding content on your site.
efficient manner.
Do not offer more than is required for the user to perform a task. Be aesthetically pleasing.
Occam’s razor: Remove or hide irrelevant or rarely needed information –They compete with important information on screen
Present information in a natural order.
Help should be:
1. Visibility of system status and losability/ findability of the mobile device 2. Match between system and the real world 3. Consistency and mapping (standards) 4. Good ergonomics and minimalist design 5. Ease of input, screen readability and glancability: 6. Flexibility, efficiency of use and personalization 7. Aesthetic, privacy and social conventions: 8. Realistic error management
Advantages
especially true if you are only going to use a single evaluator.
damage the user experience. Problems
findings may be open to debate.
may need to use less skilled evaluators whose findings may not be as valuable.
“The developer cannot predict how exactly users will interact with and perceive their application. The only way to get that kind of information is through actually having users try out their products. So, while mobile heuristic evaluation is valuable, it cannot be considered a replacement for user testing as the application is for users, and you cannot take the users
“There is a need to review the design heuristics we learn and use as newer technology comes out, and as we develop for novel devices. This is because heuristics, by the original definition at least, are often applied without putting too much deep thought into the context surrounding
principles may be more important than others, while others might be invalid.”
By 4/12 By 4/12 Using a mobile app prototyping tool (Indigo Studio), develop an interactive, full-fledged, content-rich, high-fidelity prototype of your mobile
Turn-in 1. Submit a short description of how your system works: text entry 2. Submit the direct link your final hi-fi prototype: URL 3. Submit a png file (400X250 pixel) of your logo image: File upload Assessment criteria:
1. 15% description 2. 70% Prototype
1) Quality (30%) 2) Flow (20%) 3) Contents (20%)
3. 15% Logo image
* Disclaimer. Further instruction of this submission can be given verbally during class or through Piazza. * -20% for not following turn-in instructions per submission
By 4/12 By 4/12 1. Define 3 or more major tasks and actions needed for each task
complete the task
2. Conduct Cognitive Walkthrough of your wireframe with two accessors 3. In each action, ask three questions (p24) and report findings in accordance with 5 evaluation factors (p16)
* Disclaimer. Further instruction of this submission can be given verbally during class or through Piazza.
By 4/12 By 4/12 # Turn-in: a PDF with
issues for fixing
* Disclaimer. Further instruction of this submission can be given verbally during class or through Piazza.
Format: 3-page max in PDF (except diagrams, if any), 11 point scale in Times New Roman, 1.5 line spacing
* -20% for not following turn-in instructions per submission