C1.1 / Responsibility of the designer

Cognitive ergonomics is concerned with mental processes such as perception, memory, reasoning and motor responses as they affect the interactions between humans and a product or system. Understanding psychological factors can greatly improve the quality of user-product interfaces. It may lead to better:

• Affordance - How well does a product or system make clear how it can or should be used? How intuitive is a product to use?

• Constraints - How well does a product or system restrict or avoid misuse?

• Mapping - How logical is the causality between a control and the action it triggers?

• Causality - Does the product or system provide feedback after interaction? How does the user know their action was successful (or not)?

• Conventions - How are affordance, constraints, mapping and causality understood across different groups of humans (cultures, age groups, etc.)?

The collection of psychological data involves the study of human behaviour related to their experience when interacting with a product or system. Designers can use a variety of methods for collecting such data: 

• Surveys & Interviews - Asking users or experts questions before, during and/or after interacting with the product or system. Interviews lead to recorded qualitative data in the form of notes, transcripts or audio and video recordings. Surveys lead to information that can be presented on data scales such as ratings and answer distributions.

• Standardised Testing - Asking users to achieve well-defined goals using the product or system and recording how well these goals are met. Standardised testing usually leads to recorded quantitative data resulting from checklists and measurements such as speed, duration and variance.

• Observations and Case Studies - Analysis of a prototype or already existing products or systems in use. This often comes in the form of an in-depth study of one or a few persons using a product or system. The hope is that learning gained from studying one case can be generalized to many others. It can be dangerous to generalize from such anecdotal evidence. Observations can lead to recorded qualitative data in the form of notes, photos or video footage. Or to quantitative data in the case of measurements such as duration, distance or tallying.

The psychological factor data relevant to a specific product or system is often very dependent on the exact context in which it is used. The collection of such data therefore is usually done by designers themselves: data is best gathered through primary research.

Ratio scales show the exact difference between units (Interval scales); They show the order of units (Ordinal scales), and they have an absolute zero. The difference between a ratio scale and an interval scale is that the zero point on an interval scale is some arbitrarily agreed value. In contrast, on a ratio scale, it is a true zero. For example, 0°C has been defined arbitrarily as the freezing temperature of water, whereas 0 grams is a true zero, that is, no mass. A ratio scale allows you to compare differences between numbers.  For example, if you measured the time it takes 3 people to run a race, their times may be 10 seconds (Racer A), 15 seconds (Racer B) and 20 seconds (Racer C). You can say with accuracy, that it took Racer C twice as long as Racer A. 

Psychological factor data often refers to the internal cognition of a user interacting with a product or system. It is important to acknowledge also that cognitive performance is influenced by the environment in which the interaction takes place. In short: The environment in which a user completes a task using a designed product or system impacts the success level and efficiency of performance. It can also increase or reduce the possibility of accidents.  Environmental factors may include:

• The quality of the equipment - Controls, visibility, hazards, warnings, safety guards

• Mental workload - Boredom and repetitiveness.

• Physical workload -  musculoskeletal impacts such as force, pressure and repetition.

• The physical environment  - Noise, temperature, pollutants, trip hazards, signage.

• The social and psychological environment  - Social group norms, morale.

Seemingly basic factors such as sound, light and temperature impact the performance of a product or system profoundly and in complex ways. When considering the design of an office the following can be considered:

• Install sound-absorbing acoustic partitions to keep the noise of conversations isolated.

• Isolate noisy equipment such as photocopiers and printers in a separate area. 

• Use low-sound phone tones.

• Install quiet ventilation and air-conditioning in order to control humidity and air velocity (the movement of air, still air makes people feel stuffy, moving air increases heat loss)

• Provide natural light, but make sure the environment is well-lit at all times.

• Provide indoor and outdoor views to allow vision shifts.

• Create thermal comfort through controlled air temperature  and radiant temperature (the heat transfer from human bodies - metabolic heat) by demanding appropriate clothing 

Fatigue, stress, temperature, noise levels and all other psychological factors mentioned before. have a significant impact on alertness - The level of vigilance, readiness or caution of an individual. Long repetitive tasks may lead to a lack of concentration and errors or accidents may occur. Dangerous or very stressful situations can also affect people’s ability to make correct judgments or decisions. 

Alertness is especially important in situations where human error may lead to serious consequences. This could be when the information input is high and fast or when the routine or repetitiveness of a task allows a human user to become less cautious or less ready to react to something that might happen unexpectedly.

Human error comes in several forms but two fundamental categories are slips and mistakes. Slips result from automatic behaviour when subconscious actions that are intended to satisfy goals get waylaid en route. Mistakes result from conscious deliberations. Lack of alertness is mostly associated with slips.

As a design principle, when there is a strong likelihood of forgetting a critical step in a hazardous procedure, an attempt should be made to automate that step or provide an explicit alert to complete it.

People will perceive environmental factors in different ways. While we may be able to measure an environmental factor using quantitative data (the room temperature, for example), the perception will vary from person to person.

Perception has three levels of situational awareness:

• Perception - refers to the awareness of relevant objects, people, systems or other environmental factors.

• Comprehension - understanding the meaning of what was perceived: recognizing, interpreting and evaluating the significance of that information. 

• Projection - the ability to predict what will happen in the near future, based on past experience, knowledge and understanding of the dynamic elements of the situation or environment. Situational awareness is a complex phenomenon that depends on several basic and higher-level cognitive processes.

A designer must consider the end user's needs, wants and limitations within every element of the design cycle. The ability to identify how users will interact with a product, service or system is vital for its success. To achieve this, designers must be able to acquire and analyse valid data without making assumptions about how the product may be used. The ability to put aside one’s own ideas and biases is essential for UCD. Designers must act with integrity and not project their own ideas of what the user requirements are when trying to create technological solutions to their problems

User-Centred Design (UCD) is a design process that pays particular attention to the needs of potential product users through the involvement of users at all stages of the design process. It considers how users are likely to use the product and tests products with actual users. Sometimes called “empathic design”, the user-centred approach puts the design team in direct contact with the people they are designing for, that is, to empathize with potential users and gain a better understanding of their thoughts, needs, values and beliefs. The design team often includes anthropologists, ethnographers and psychologists to advise the creative designers.

When following a UCD approach to the design process:

• A design is based on an explicit understanding of users, tasks and environments.

• Users are involved throughout design and development.

• The design is driven and refined by user-centred evaluation.

• The process is iterative.

• The design addresses the whole user experience.

• The design team includes multidisciplinary skills and perspectives.

UCD focuses on better mainstream solutions for everyone rather than providing different solutions for different user groups ('special needs design'). Inclusive design ensures there that there is a sufficient market for a product and increases its feasibility as an innovation.

Demographic change is a major challenge for designers. There are already over 130 million people over 50 in the EU alone. This means that one in every two adults will be over that age. The rapid ageing populations and growing numbers of people with disability are having a profound effect on new product and service design. Designs that include the needs of marginalised groups of people is regarded not only as socially desirable but also as a commercial opportunity. If you design products for people with no difficulties, you are then excluding a large portion of the population. It makes no commercial sense to do so.

Inclusive design requires designing universally acceptable products, including those with physical, sensory, cognitive and other challenges and impairments.

A user trial involves the observation of people using a product and the collection of comments from those who have used the product. In user observations a person's behaviour is often just as important as the collection of their comments. You can observe a person using a product and not ask for comments, this would still be a user trial. 

Users can be given products to test over a period of time. This is often done as part of commissioning new products or redesigning an old product. Manufacturers obtain feedback from users to see if the design or existing product meets the needs of that target market. The manufacturers can then identify and rectify any problems with the product before mass production goes ahead and the product enters the market.

User trials usually create primary quantitative data collected by questionnaire or interview if you require more qualitative data. User trials and observations are useful and appropriate for gaining information on ease of use (ergonomics), performance, price, and aesthetics. The usability of the products can be tested, to find out how it is used and abused in a real-world context. Users can identify strengths and weaknesses in a product. The product can be a prototype but must have significant functionality in order to be meaningfully used in user trials.

A common method of collecting user responses is through interviews or questionnaires. These are similar to user trials in that users/consumers are directly involved. However, in this case, the user merely answers questions posed to them about a product or context, but they may not have to have interacted with the actual product. 

Interviews and questionnaires conducted by a designer are a form of primary research and can gather both qualitative and quantitative data. They are particularly important when trying to establish a design ‘need’, when formulating the Design Brief and Design Specifications.

Focus groups are facilitated sessions with a group of individuals from a target audience brought together to discuss specific elements of your product and user experience. Focus groups are usually more focused on the usability of the product than on user preferences as they only involve a small sample of users. Focus groups can be used at many stages of the design process and are focused at gathering quantitative data.

For example, a prototype may be shown to a group of users who are then asked to give their views on it, to compare it to other similar products with which they may be already familiar. This will give the design team some indications of how a user responds to their product, both positively and negatively. Less specific preferences or attitudes can be explored by asking a group to discuss more general features of a broad product type, using open questions like, “What annoys you the most about lawnmowers?” or “Which gardening activities would you like new products to help you with”. 

Testing Houses provide formal, often government or industry-certified, testing services. Testing houses might provide licenses to sell or produce a product in a particular market. Testing houses usually focus their testing on quantifiable data. This data is gathered with scientifically valid and reliable testing methods by (certified) industry experts. Usability laboratories provide a more exploratory form of testing focussing more on qualitative data.