Representational Efficacy and Error Dynamics in Observational Drawing

A Quantitative Method for Drawing Accuracy Evaluation

  • Raquel Pelayo Faculty of Architecture (FAUP) and Faculty of Fine Arts (FBAUP), Universidade do Porto


This paper presents a quantitative method for assessing observational drawing accuracy, as a more objective alternative to evaluation by expert panels. The method, design process and testing revealed insights about representational efficacy and error dynamics which may inform teaching and research. The method was used to assess and compare the efficacy level of apprentices drawing the same subject. It involves disassembling shape into partial aspects – using four graphic properties - that influence the overall representational efficacy, and comparison to photographs taken from the draughtsman’s viewpoint. This process has proven useful to: a) distinguish which parts of the drawing are accurate; b) specify the formal aspects that compromise representational accuracy, and to what extent, and; c) identify and quantify types of error. The research extends existing methods and is comprehensive in detecting 2D representational errors. The findings also suggest that certain kinds of error can give rise to others, based on some kind of “logic of compensation” process that might happen unconsciously during the task. This deserves further research.

How to Cite
PELAYO, Raquel. Representational Efficacy and Error Dynamics in Observational Drawing. TRACEY, [S.l.], v. 9, n. 2, p. 1-15, dec. 2014. ISSN 1742-3570. Available at: <>. Date accessed: 18 june 2019.