We conclude with some suggestions about methods that might be used to minimize these errors. The most frequently employed recording technique is probably photography. But freehand drawing has been a popular rock art recording technique for many years. Some of the criteria used to evaluate these technologies include image completeness, geometric and content accuracy and efficiency. By image completeness, we mean recording all properties of the object even when the glyph is very faint or difficult to decipher.
Drawing has the advantage of being inexpensive and requiring little extra equipment.
This, of course, has both positive and negative consequences. That is, the subjectivity of interpretive conventions can become a help to fill in missing data but can also lead to serious errors. Faintness and superposition are common problems in rock art that are perhaps best overcome by drawing and tracing techniques. Drawing, sketching or drafting is likely to be inaccurate even if methods are tightly regulated. Drawing also has the disadvantage of requiring substantially more time and skill by the recorder than does photography.