- Human psychology is complex and varied.
- Designers often struggle to classify people into groups because:
- Psychological traits are broad and may not apply to everyone.
- Data on touch, taste, and smell are often subjective.
Design permeates every aspect of human experience, making it essential to consider psychological factors.
- Analyze the human information processing system.
- Identify potential breakdowns and their effects.
Focus on how psychological factors influence user interaction with products.
Designers use various methods to gather psychological data:
- Interviews: To understand beliefs and experiences.
- Surveys: To collect consistent data from multiple participants.
- Observation: To see how users interact with products in real-time.
- Standardized Tests: To measure performance or ability.
- Purpose: Categorizing the survey-taker into groups
- Examples: Which city do you live in? / What is your gender?
- Characteristic: No numerical value, factual e.g., not an opinion
Which city do you live in:
- London
- New York
- Tokyo
- Hong Kong
- Other
- Purpose: Only to show order / ranking only
- Examples: Satisfaction levels (unhappy to happy).
- Characteristics: It's to figure out ranking and not intensity or difference e.g. someone who rates themselves a 5 on most satisfied is not necessarily 5 times happier than someone who rated themselves a 1
A survey asking users to rank their satisfaction from 1 (least satisfied) to 5 (most satisfied) uses an ordinal scale
... kind of like if you scrolled to the end of this article and told us how much you like /dislike this with our emoji system :)
- Purpose: Shows both the order and the difference but no absolute zero
- Examples: Celsius temperature on a thermometer
- Characteristics:
- No absolute zero - on a thermometer we only set 0 degrees as "zero" because it's the freezing point of water
- The point is that 10 degrees is warmer (as it's a bigger number) than 0 degrees, and that the difference between 10 and 0 is the same interval as the difference between 20 and 10
The interval difference between 10 to 20 degrees is the same as between 15 to 25 degrees.
- Purpose: Comprehensively order, differences and has absolute zero
- Examples: Weight, speed.
- Characteristics: Absolute zero, equal intervals and ordered
Ratio scales provide the most detailed quantitative data.
A speedometer measures speed with an absolute zero point
- Order: Obviously 60 km/h is higher than 50km/h
- Difference: The interval between 60 km/h to 50 km/h is the same as 40 km/h to 30 km/h
- Absolute zero: 0 km/h means you're stationary and not going anywhere thus is a real zero
Understanding scales helps designers:
- Evaluate data collection methods.
- Ensure data is meaningful and applicable.
- Choose the right tools, such as surveys or observations.
Designers need to know how they collect data
- What type of data will you gather?
- Qualitative or quantitative?
- Which scale should be used to gather this data?
- Ratio, ordinal, interval, or nominal?
- What tools will you use to gather this data?
- Surveys, interviews, measuring tools, thermometers etc.?
- The human brain is basically a computer with inputs, processing and outputs
- How humans process then act on information
- Input: Receiving information.
- Processing: Analyzing the information.
- Output: Responding or acting.
- Think of Jojo as a real human tutor ... (it's actually AI but you get the point)
- Input: Whatever you type into the chat box
- Processing: Analyzes what your wrote
- Output: Explains stuff to you as text, or a flow chart diagram or gives you a quiz / flashcards if helpful
If overwhelmed with too much information, the system can break down, leading to errors. E.g., A driver trying to answer a phone while navigating traffic may miss important signals, causing an accident.
- Input Stage:
- Information is generated or received by the human senses.
- Sensory Processing Stage:
- Human senses (touch, sight, sound, smell, taste) detect and take in the information.
- Central Processing Stage:
- The brain processes the information and makes a decision based on memory and prior knowledge.
- Motor Processing Stage:
- The nervous system sends signals to muscles to execute an action.
- Output Stage:
- A physical action is carried out based on the decision made.
- Stimulus: The pan is smoking, indicating it's too hot.
- Sensory Processing: Eyes see smoke rising from the pan.
- Central Processing: The brain recalls that high heat can burn food and decides to lower the flame.
- Motor Processing: The nervous system sends signals to the hand muscles to turn down the stove knob.
- Output: The stove temperature is reduced, preventing the egg from burning.
- Stimulus: A glass is slipping from the table.
- Sensory Processing: Eyes detect the motion of the falling glass.
- Central Processing: The brain quickly assesses that the glass will break if it hits the ground and decides to catch it.
- Motor Processing: The nervous system sends signals to the arm and hand muscles to move quickly toward the glass.
- Output: The person grabs the glass before it hits the floor, preventing it from breaking.
- Age: Young users may lack skills; older users may forget them.
- Strength: Some tasks require physical strength.
- Skills: Complex tasks need practice.
- Health: Physical or mental health can impact performance.
A child may struggle to turn a stiff dial due to undeveloped fine motor skills.
- Environmental factors like sound, temperature, and lighting also affect user performance
- Alertness
- Temperature: Too hot causes drowsiness; too cold increases alertness.
- Sound: Loud noises distract; repetitive sounds irritate.
- Lighting: Poor lighting strains eyes.
- Air Quality: Dusty air hinders breathing.
- Smell: Unpleasant odors distract.
- Perception
- People perceive environmental factors differently. While temperature can be measured, comfort levels vary.