These are notes from the edX course “Principles of Designing for Humans” – Week 1 & the first half of Week 2.
- Visual Perception Part 1 + 2
- Memory Part 1 + 2
- Seven Stages of Action
- Gulfs of Execution and Evaluation
The “central vision” part of the human field of view is about 5 degrees. In that field, people can read text and recognize details in images. Beyond that, we see vaguely value (shade), color, and shape.
When an object is easy to recognize in a visual field, this is likely due to contrast between that object from all other objects inside and outside of our visual field, so it is related to features listed above, like color, shape, value, and (also) texture (internal shape) This is called Pop Out.
Proximity is not considered a primitive visual feature that is processed in the first, and fastest, stage of visual processing. Angle of intersection, shade/contrast, and motion are.
According to the original research on short-term memory, about 7 ‘items’ can be retained in short-term memory at one time.
Consistency, standards, and metaphor are recommended because they allow a design to take advantage of users’ existing schema (more below in “learning”)
Memory & Learning
- Keep lists of options short
- Give users tools for reducing options
- Don’t expect users to remember things
2 methods for learning
- Association – associating new things, with things we already know
- Repetition – for when no associations exist, we repeat (memorization aka elaborative rehearsal)
Memory is associative. A network of associated concepts is a schema.
Likelihood of remembering is based on 3 things
- Strength of association (what does this mean, really?)
Learning will work better if a learner can fit it into an existing schema
- Use metaphors
- Leverage standards and consistency
- Avoid asking users to memorize shit
- Prefer recognition over recall
- Eg: shopping carts
- People have an easier time recognizing options they’ve seen before, than recalling it from memory with no prompting
- Leverage Consistency and Standards
- Across products, and different parts of the same products
Concepts related to human visual processing and memory:
- primitive visual features: color, contrast, angle, length, slope of lines, texture, motion
- gestalt principles for pattern-forming: proximity, closure and continuation, symmetry, common fate, similarity, common area
- characteristics of short-term memory: size and duration
- characteristics of long-term memory: association, schema, recall, elaborative rehearsal
Stages of Action
In Don Norman’s “Design of Everyday Things” – we have the 7 stages of action.
- Forming a goal
- Forming intention
- Selecting an action
- Executing the action
- They change the world in some way
- Perceive the change in the world
- Interpret the state of the world
- Evaluate the outcome
Steps 2-4 are on the side of Execution
Steps 5-7 are on the side of Evaluation
Between them is “The Gulf”
The Gulf of execution as being the challenge when trying to map their goals on possibilities in the world to help them accomplish their goals.
The Gulf of evaluation is trying to interpret the state of the world whether their actions were successful in moving them closer to their goals.
Bridging the Gulf
- User goals
- How they think about accomplishing them
If we understand users’ goals, what they’re trying to accomplish here, and how they frame it, we can make sure that essential actions they need and/or expect will be readily visible, available, and framed in language or images they associate with their goals.
Make sure likely actions are
- Visible when needed
- Make sense
Make sure the results of actions
- Are visible
- Make sense
It’s also important that they understand what will happen when they execute, and that the feedback they’re getting indicates whether their actions were successful, and that the actions are leading them towards or away from their goals.