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The Psychology of Everyday Things
Two of the most important characteristics of good design are: Discoverability - it is possible to even figure out what actions are possible and where and how to perform them. Understanding - What does it all mean? How is the product supposed to be used? What do all the controls and settings mean?
- Industrial Design: creating concepts and specifications that optimize function, appearance and value of products
- Interaction Design: how people interact with technology. Answer what can be done? What has just occurred? What is happening?
- Experience Design: design products, services with the focus on quality and enjoyment.
Design is how things work, and how they are controlled, and the interaction between people and technology.
Deficiency is often because design is done by engineers who are experts in technology but lack the understanding of people.
Human Centered Design (HCD) - approach that puts human needs, capabilities and behaviours first, and accommodates design.
HCD - is a philosophy and procedures whereas others are areas of focus. HCD whatever the service or product looks to incorporate human needs.
When interacting with a product we need to understand how it works. This means understanding what it does, works, and what operations are possible.
Discoverability results from five fundamental processes:
- Affordances: - relationship between physical object and person. Affordance is not a property but a relationship. Represents the possibilities of how an event can interact with a person.
- Signifiers - communicate where the action should take place. The term signifier refers to the mark, sound, or anything that communicates the behaviour to a person. Signifiers are the perceived affordances such as a handle door knob.
- constraints - things that can effect good design.
- mappings - relationship between the elements of two sets of things
- Feedback - communicating the results of an action. Feedback must be immediate, prioritized and also informative.
- Conceptual Model - an explanation on how things work. Clues come from their perceived structure (meaning 1 - 5 above)
The Psychology of Everyday Things
When people using something they face two gulfs: the gulf of execution, where they try to figure out how it operates, and the gulf of Evaluation, where they try to figure out what happened.
There are two parts to an action: executing the action, then evaluating the results: doing and interpreting.
There are three stages of execution that follow from the goal: plan, specify and preform. Evaluating what happened has three stages: perceiving what happened, trying to make sense of it and finally comparing what happened with what was wanted.
Seven stages of action: one for goals, three for execution, and three for evaluation.
Route cause analysis: asking why until the ultimate fundamental cause of the activity is reached.
Most of the brain's operations are subconscious, hidden beneath our awareness. It is only highest level, what I call reflective, this is conscious.
We believe all human thought is conscious. But it's not. We also believe we can separate thought from emotion. This is false. We cannot separate cognition and emotion. Cognitive thoughts lead to emotions: emotions drive cognitive thoughts.
Model of human cognition and emotion is to consider three levels of processing: visceral, behavioural and reflective.
Most basic level is visceral - the system allows us to respond quickly and subconsciously, without conscious awareness or control. For designers, the visceral response is about immediate perception.
The behavioural level is the home of learned skills, triggered by situations that match the patterns. For designers, the most critical level is that we associate every action with an exception.
The reflective level is the home of conscious cognition. Reflection is cognitive, deep, and slow. Reflection is perhaps the most important of the levels of processing.
Understanding arises at a combination of the behavioural and the reflective levels. Enjoyment requires all three.
Everyone forms stories to explain what they have observed.
Learned helplessness - it refers to the situation in which people experience repeated failure to task.
To fail is to learn: we learn more from our failures than successes.
7 Stages of Action
- What do i want to accomplish
- What are the alternative action sequences
- What action can I do now
- How do I do it
- What happened
- What does this mean
- Is this okay, Have I accomplished my goal
The information helps answer questions of execution (doing) is free forward. The information that aids in understanding what has happened is feedback.
The insights of seven stages of action leads to seven fundamental principals of design.
- Conceptual Model
Knowledge in the Head and in the World
Precise behaviour can emerge from imprecise knowledge for four reasons:
- Knowledge is both in the head and in the world
- Great precision is not required
- Natural constraints exist in the world
- Knowledge of cultural constrains and conventions exists in the head
People function through knowledge of and knowledge how.
Knowledge of - (declarative knowledge) includes the knowledge of facts and rules.
Knowledge how - (procedural knowledge) is difficult or impossible to write down and difficult to teach. It is best taught by demonstration and best learned though practice.
Psychological research suggests that people maintain only partial descriptions of the things to be remembered.
What appears good can still fail when introduced to the world. Sometimes bad products succeed and good ones fail.
Two major classes of memory; short and long term.
Procedural memory: a memory of how we do things, as opposed to declarative memory, the memory for factual information.
Memory for arbitrary things.
Memory for meaningful things.
Three levels of mapping, arranged in a decreasing effective as memory aids:
- Best Mapping: Controls mounted on the item.
- Second-best: Controls are as close as possible to the object
- Third-best: Controls are configured in the same spatial configuration.
Knowing What To Do: Constraints, Discoverability, And Feedback
Four classes of constraints: physical, cultural, semantic, and logical.
Why does inelegant design persist for so long? Legacy problem - too many devices use the existing standard.
Semantic Constraints: are those that rely on the meaning of the situation to control the set of actions?
An useable design starts with careful observations of how the tasks being supported are actually preformed, followed by a design process the results in a good fit to the actual ways the tasks get performed. The technical name is task analysis.
Forcing Functions: are a form of physical constraint: situations in which the actions are constrained so that failure at one stage prevents the next step from happening.
People invariably object and complain whenever an alternative approach is introduced into an existing array of products and systems. Conventions are violated and new teachings are required.
Skeuomorphic is the technical term for incorporating old ideas into new technologies, even though they don't play a functional role.
Human Error? No, Bad Design
Why is there an error? The most common is in the tasks and procedures that require people to behave in unnatural ways.
Root Cause Analysis: investigate the accident until the single, underlying cause is found.
Use the five why's technique.
When people err, change the system so that type of error will be reduced or eliminated. When complete elimination is not possible, redesign to reduce the impact.
We define human error as any deviance from behaviour.
Error is the general term for all wrongdoing.
There are two major classes of slips: Action-based and memory-lapse.
Mistakes have three major classes: rule-based, knowledge-based, and memory-lapse.
Slips are the result of subconscious actions getting waylaid en route. Mistakes result from conscious deliberations.
Different action slips:
- Capture slips - the situation where instead of a desired activity a more frequently or recently performed one gets done instead: it captures the activity. Capture error are partial memory lapse errors.
- Description-similarity slips: the error is to act upon an item similar to the target. Memory lapse failing to do all the steps in a process, repeating steps, forgetting the action or the goal/plan.
- Mode errors - occurs when a device has different states in which the same controls have different meanings: we call these state modes. Mode error is inevitable in anything that has more possible actions than it has controls or displays.
Designers must always compensate for interfering activities.
Danish engineer Jens Rasmussen distinguished three modes of behaviour:
- Skill-based: occurs when workers are extremely expert in their jobs. Most common in skill based behaviours is slips,
- Rule-based: occurs when normal routine is no longer applicable but the new situation is one that is known, so there is already a well prescribes a course of action, a rule. Rules simply might be learned behaviours from previous experiences. This type of error can be a slip or mistake. If the wrong rule is elected then this would be a mistake. If the error occurs during execution, it is most likely a slip.
- Knowledge-based: occur when unfamiliar events occur where neither existing skills nor rules apply. In both rule and knowledge-based situations the most serious mistakes occur when the situation is misdiagnosed.
Knowledge based mistakes: behaviour takes place when the situations novel enough that there are skills or rules to cover it. In this case, a new procedure must be devised.
Memory lapse can lead to mistakes if the memory failure leads to forgetting the goal or plan of action. Mistakes often arise from ambiguous information about the current state of a system, the lack of a good conceptual model, and inappropriate procedures.
A major source of error, especially in memory-lapse errors is interruption.
Multitasking, whereby we deliberately do server tasks simultaneously, erroneously appears to be an efficient way of getting a lot done.
What can a designer do? Make the item being acted upon more prominent. Make the operation reversible.
Slips most frequently occur when the conscious mind is distracted, either by some other event or simple because the action being preformed is so well learned that can be done automatically without conscious attention.
Many slips can be minimized by ensuring that the actions and their controls are as dissimilar as possible or at least as physically far apart as possible.
Key Design Principles:
- Put the knowledge required to operate the technology in the world
- Don't require that all the knowledge must be in the head. Allow for efficient operation when people have learned all the requirements when they are experts who can perform without the knowledge in the world, but make it possible for non-experts to use the knowledge in the world. This will also help experts who need to perform a rare infrequently performed operation or return to the technology after a prolonged absence.
- Use the power of natural and artificial constraints: physical, logical, semantic, and cultural. Exploit the power of forcing function natural mappings.
- Bridge the two gulfs, the Gulf of Execution and the Gull of evaluation. Make things visible, both for execution and evaluation. On the execution side, provide feed-forward information: make the readily available. On the evaluation side, provide feedback: make the results of each action apparent. Make it possible to determine the sis readily, easily, accurately, and in a form consistent with team's status, the person's goals, plans, and expectations.
Good designers never start by trying to solve the problem give to them: they start by trying to understand what the real issues are. As a result, rather than converge upon a solution, they diverge studying people and what they are trying to accomplish, generating an idea, after idea, after idea.
human-centered design, is to ensure that the result fits human desires, needs, and capabilities.
Designers resist the temptation to jump immediately to a solution for the stated problem.
Instead, they first determine what basic, fundamental (root) issue needs to be addressed. They don't search for a solution until they have determined the real problem, and even then, instead of solving that problem, they stop to consider a wide range of potential solutions. Only then will they finally converge upon their proposal. This process is called design thinking.
HCD is a procedure for addressing these requirements, but with an emphasis on two things: solving the right problem, and doing so in a way that meets human needs and capabilities.
Iterate through the four stages of observation, generation, prototyping and testing.
The design council divided the design process model into four stages: discover and define for the divergence and convergence phases of finding the right problem and develop and deliver for the divergence and convergence phases of finding the right solution.
Four activities in the human centered design process:
The design researcher will go to the potential customers, observing their activities, attempting to understand their interests, motives, and genuine needs. Applied ethnography.
Idea generation: Generate many ideas, be creative without regard for constraints. Question everything.
How many people should be studied? Opinions vary, but my associate, Jakob Nielsen, has long championed the number five: five people studied individually. Then, study the results, refine them, and do another iteration, testing five different people.
How can we pretend to accommodate these very different, very disparate people? The answer is to focus on activities, not the individual person. I call this activity-centered design.
Activity- centered approach is human-centered approach, far better suited for large, non-homogeneous populations.
Psychologists Charles Carver and Michael Scheier suggest that goals have three fundamental levels that control activities. Be-goals are at the highest, most abstract level and govern a person's being: they determine why people act, are fundamental and long lasting, and determine one's self-image. Do-goals determine the plans and actions to be performed for an activity. The lowest level of this hierarchy is the motor-goal, which specifies just how the actions are performed
iterative method of human-centered design, where the process is circular, with continual refinement, continual change, and encouragement of backtracking, rethinking historic decisions.
Sometimes this is not even possible because critical knowledge about project decisions and methods are in the form we call implicit knowledge;Within the heads of the workers.
Living with Complexity, in which I argued that complexity is essential: it is a confusion that is undesirable. I distinguished between "complexity," which we need to match the activities we take part in, and "complicated," which I defined to mean "confusing."
Design In The World of Business
Creeping featurism is the tendency to add to the number of features of a product, often extending the number beyond all reason.
A better strategy is to concentrate on areas where they are stronger and to strengthen them even more. Then focus on all marketing and advertisements to point out the strong points.