Figure 3 . Participant performing an exploratory procedure known as contour following ( Lederma et al 1993 ). The drawing of the hammer is by a University of Cape Town student made during an on-campus HVOD workshop .
Figure 4 . Evaluation of participants ’ drawings by the instructor . ( A ) and ( B ) show Effective observation of the hammer by participants indicated by the descriptive value of the marks ; how well the marks ( singly and in combination ) describe the form of the hammer .