Previous research has shown that encouraging learners to explain material to themselves as they study can increase their understanding. Furthermore, different types of material (e.g. text or diagrams) influence learners' self-explanation behaviour. This study explores whether the coherence of text impacts upon the self-explanation effect. Forty-eight low-knowledge learners (university students) learnt about the circulatory system with text that was designed to be either maximally or minimally coherent. Half of these learners also received self-explanation training. Results showed that learners given maximally coherent text learnt more, as did learners who self-explained. However, this was not because coherent text increased self-explaining. Instead minimally coherent text significantly increased the number of self-explanations that learners made. It is suggested that self-explaining in the minimal text condition served to compensate for weaknesses and gaps in the text, whereas self-explaining in the maximal text condition may have led learners to detect flaws in their mental models and repair them. Consequently, rather than providing a minimally coherent text which compels low knowledge learners to self-explain to overcome its deficits, we should instead encourage learners to self-explain from well structured and explicit text.