Perception (DP IB Theory of Knowledge): Revision Note

Perception

• Human perception is based on sensory organs that can detect a limited range of stimuli; sensory organs include:

  • eyes

  • ears

  • mouth

  • nose

  • skin

• Perception is a process of interpretation: we observe stimuli, and then our brain interprets the information

  • The senses can miss information altogether, so knowledge claims based only on “what we see” may be incomplete or unreliable

• Perception can be affected by factors that can reduce the reliability of observations, e.g.:

  • tiredness 

  • illness 

  • strong emotion

  • bias

• Recognising sensory limits encourages knowers to ask what might be hidden or distorted in their experience

Selectivity & expectation

• Perception can be influenced by individual selectivity and expectations

  • Selectivity means that attention focuses on some stimuli while ignoring others

  • Expectations and prior beliefs act as filters, increasing the likelihood that knowers will notice information that fits with what they already think

    • Expectations can create perceptual illusions, where knowers “see” patterns or meanings that are not really present

• Being aware of selectivity and expectation helps knowers question their perception of evidence

Differences in interpretation

• Different knowers can interpret the same sensory input in different ways due to, e.g.:

  • culture 

  • language

  • personal history

• Personal experiences and values shape what individuals consider to be relevant, credible or offensive in what they perceive

• Group membership and shared perspectives can create common interpretations, but these may not be shared by outsiders

• Recognising interpretive differences encourages knowers to compare perspectives and ask how subjective their own view might be

Tools extending perception

• Technologies such as microscopes, telescopes and sensors extend human senses beyond their natural limits

  • These tools allow knowers to detect phenomena that are too small, distant or faint for unaided perception

• Perceptual tools can increase the precision and quantity of data, but they also introduce new sources of error and bias

• Knowers need to understand how such tools work in order to judge how far their outputs can be trusted