Technical Translation: Usability Strategies for Translating Technical Documentation

The Boundaries of Visual Processing 
The basic principle underlying human sight is the reception of light re-
flected from the physical world. But this is only a small part of the visual 
channel. This light represents a stimulus which must then be interpreted. 
What makes this channel so valuable is what we do with the information 
we perceive. This information must be processed and transformed so that 
we can form an interpretation of the images we see. 
In processing visual information, our expectations, experience and 
knowledge play a key role. For example, if we know that a truck is 15 feet 
high and 40 feet long, we will always perceive it as such even if we view it 
from a distance. It is this ability which allows us to make sense of unex-
pected, faulty, contradictory or incomplete information and allows us to re-
solve ambiguous information. Our expectations in relation to the world 
around us are largely determined by the context. Accordingly, one set of 
criteria may apply in one particular situation, e.g. a truck appears huge and 
has a trailer and 18 wheels when viewed up close, while different criteria 
apply at other times, e.g. a truck appears small and has a trailer and 18 
wheels when viewed from a distance.
Figure 4: The Ponzo Illusion 
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The Human Cognitive System
Unfortunately, this ability to make sense of ambiguous or contradictory 
information is not perfect and is prone to errors and interference. This can 
be illustrated by optical illusions such as the Ponzo illusion (Figure 4) where 
the top line appears longer than the bottom line when in fact both are the 
same length. This can be attributed to an incorrect application of the law of 
constancy whereby the top line seems further away and is made to appear 
bigger (Dix 1998:19).
Figure 5: The Proof-reading Illusion (Dix 1998:21) 
In the proof-reading illusion, most people reading the sentence quickly will 
miss the second “the”. However, on closer examination, people will spot 
the mistake. This is an example of how our expectations compensate for 
unexpected information when reading.