This preferred outcome can 
be explained on the basis of 
"good continuation," a 
principle of grouping Max 
Wertheimer uncovered in 1923. 
Good continuation refers to our 
tendency to group together in a 
single structure those parts or 
units that appear to be aligned 
with, or smooth directional 
continuations of, one another, 
other things being equal. As a 
glance at the figure at left will 
indicate, contours that 
constitute abrupt 
discontinuities of direction 
tend not to be regarded as parts 
of the same overall structure. 
Because we tend to perceive in 
accordance with this principle, 
it seems plausible to conclude 
that we generally recover in 
our perceptions the same 
structures and groupings that 
exist in the world. That is 
because such smooth 
continuations ordinarily are 
inherent in parts of the same 
object. It would be coincidental 
for these continuations to exist 
within the retinal image when 
they result from objects or parts 
that have no connection with 
one another. Of course, it is 
entirely possible that two bent 
sticks are partly hidden by a 
tree, even though we favor the 
perception of two crossing 
sticks.  In this case, good 
continuation would result in a 
camouflage of the actual state 
of affairs. In fact, camouflage, 
both as it occurs in nature and 
as it is produced by humans, 
makes use of the principles of 
organization to yield perceptual 
objects different from the 
actual objects present, either 
by obscuring actual objects or 
by creating perceptual objects 
not actually present.