We examine the equivalence of two construct‐a‐concept‐map techniques: construct‐a‐map with created linking phrases (C), and construct‐a‐map with selected linking phrases (S). The former places few constraints on the respondent and has been considered the gold standard; the latter is cost and time efficient. Both their products and processes are compared quantitatively and qualitatively as to total accuracy score, individual proposition scores, proposition choice, map structure complexity, proposition generation rate, and proposition generation procedures. We conclude that the two mapping techniques are not equivalent: The C technique is better than the S technique in capturing students' partial knowledge, even though the S can be scored more efficiently than C. Based on their characteristics, if used as an assessment tool, the C technique is more suitable for formative assessment while the S technique is a better fit for large‐scale assessments. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 166–184, 2005