Prior testing potentiates new learning, an effect known as test-potentiated new learning (TPNL). Research using lists of related words has established that testing, by free recall, also increases semantic clustering of later recall output. It has been suggested that this is evidence that testing induces a strategy change in encoding and retrieval towards greater conceptual organisation. The current research evaluated whether this conceptual strategy change explains TPNL in three experiments. We found a) that a retrieval task that did not increase semantic clustering (list discrimination) consistently produced TPNL, and b) that factors (word-relatedness and list structure) that influenced the amount of semantic clustering had no effect on the magnitude of TPNL. These results suggest that conceptual strategy change is neither necessary nor sufficient for TPNL and is more likely to be an effect of testing, rather than a cause of TPNL.