2) Principles of Designing for Humans
This was another class where I attempted to use an idea similar to Retrieval Practice while studying the content. Essentially, I would watch a video all the way through and then try and write down anything that I remembered. I would then rewatch the video and stop the video to take notes. I found this to be helpful but it did take more time to “get through” the material. Mid-way through the week, I moved to just stopping the video and taking notes. I picked up the process again in the following weeks. Here are some of my takeaways from the material.
Week 1: Visual Perception and Memory. The visual perception of the human brain is limited. We only have a five degree of central vision range of full focus. Peripheral vision can’t be used for reading it is too out of focus. You must jump around to read. Humans scan pages using eye fixations to move from one word to the next these are called “sa-ka-ds” (saccades). We don’t usually look at the whole page we look at what is most important for us when completing a specific task. Just because something is on a page it does not mean it will be read.
Based on research by Jacob Nielsen the most common pattern of reading on the web is the F shape (for left-to-right languages). Some important principles to remember are:
- Make important info and actions visible: If something is not visible users can’t interact with it.
- Leverage how users read: Am I using these patterns?
- When evaluating ask yourself “did they see it?”, Can they find it? , Did they misunderstand what it meant?
Visual psychology suggests several stages of visual perception. We move from photons to images. The three stages are:
- Recognizable Objects
According to the course, the Gestalt School of Psychology studies the way that pattern works and created a set of principles on how the eye breaks up the visual field. These principles are:
- Proximity (nearness means the items are associated)
- Closure and continuation (we fill in gaps with likely solutions and context helps. Bk means back in the sentence “be right back”)
- Symmetry (we see something like a single object)
- Similarity (like things are part of a group)
- Common area (share a common boundary seen as a group)
- Common fate (move together those are a different pattern)
Moving from visual perception to memory requires attention and moving from short-term to long-term memory. Our short-term memory is limited and according to Miller the magic number 7+/-2 items (Miller’s Law 1956). Cowan reduced this number to 4+/-1 (Cowan, 2010). Anything that isn’t retained is lost. Learning happens when we move something from short to long-term memory.
Short-term memory is limited. Here are some UX principles based on this idea. (Attention)
- Keep lists of options short: Keep within the range of magic numbers
- Give users tools for reducing options
- Compare against each other
- Don’t expect users to remember stuff (from one screen to the next)
There are several ways to transfer something to long-term memory these include association and repetition.
Learning will work better if the learner can fit the new material into a schema
- Use metaphors: An example is the shopping cart on Amazon
- Leverage standards and consistency: Menu structure: Use one system can transfer information to the next.
- Avoid asking users to memorize information
Prefer recognition over recall
- Search terms we need to create but Google added autocomplete search terms.
These ideas come from cognitive psychology. I really like these ideas for the principles they provide but I’m not sure we really have all the answers on how the mind and senses work.
Week 2 Norman’s model of Action, the Gulfs of Execution and Evaluation, and Design Principles
In Don Norman’s book The Design of Everyday Things, he describes a seven stage model of action anyone takes to accomplish an outcome. These steps are:
- Determine a goal
- Choose a path
- Look at the world for feedback
- Determine if you were successful
- Act again
Elaborating on Norman’s model of actions the model can be divided into two parts: actions that the user takes to change the world and the feedback the user gets from the world of that action.
- The gulf of execution is that the user can see they’ve done an action in the world.
- The gulf of evaluation is the signal the world or system provides back because of that action. Did this action get me closer or further away from my goal?
Discoverability is the way we bridge the gulfs of execution and evaluation.
- Execution: users can figure out (discover) what actions are possible
- Evaluation: users can discover whether the actions were successful
Principles supporting discoverability
- Affordances: the feature of an object or environment that indicates the possibility of action.
- Signifiers: Message of what will happen if you take this action.
- Feedback: users need to know that the system heard them and will do something about their action.
- Constraints: You can only take certain actions.
- Conceptual Models: support simulation of future actions because they understand how the system is set up.
- Consistency: What users learn in one place they can apply to another.
- Metaphor: Rapidly communicate an idea about a function
Week 3 Nielsen’s Heuristics for Design
There are lots of guidelines for usability but the downside about guidelines is that they are very detailed and very specific. For example, Usability.gov has around 300 guidelines. Created by Nielsen (1994), heuristic evaluations offer an alternative to formal usability testing and are “cheap, fast, and easy to use” (p. 24). Heuristic evaluations are a discount method for highlighting usability issues in a user interface so they can be dealt with as part of the iterative design process (Nielsen, 1994).
Jacob Nielsen’s 10 heuristics cover the most important areas to consider and are generalizable. His list is derived from a systematic review of usability problems, is intended to be small and complete, able to be taught in a few hours and is well-supported by theories of perception and cognition. You can read them in 10 Heuristics for User Interface Design
Week 4 Heuristic Evaluation and Report
Most heuristic evaluations include several segments. The initial segment involves training evaluators to understand Nielsen’s heuristics. The evaluators then conduct their analysis during the second segment. The analysis is then followed by a debrief where the evaluators discuss their findings with each other. The fourth and final part includes evaluators assigning severity ratings to the usability problems (Nielsen, 1994, p. 38).
The Designing for Humans course included most but not all of these segments. I was trained on Nielsen’s heuristics, conducted an analysis of the edX discussion board, and individually assigned severity ratings to the issues. A debriefing on the issues occurred asynchronously in the form of peer reviews of usability problems with other evaluators. The only one of Nielsen’s segments not included in this evaluation is a collaboration among a team of evaluators to agree on the issues together and then assign a severity score.