The main "objective" of this work, carried out as part of a series aimed at identifying teachers' ideas on assessment, was to identify social science teachers' ideas on how causal understanding should be assessed when assessing "for" learning. After establishing the psychological model from which teachers' ideas should be evaluated, 68 secondary school teachers were asked to design assessment situations adequate for the mentioned purpose. Results showed convergence of data coming from Brazil and Spain and enlightened specific characteristics of teachers' ideas on causal understanding assessment. So they are useful for designing teachers' training programs on students' assessment. (Contains 3 tables and 2 figures.)