Pre-service teachers around the world need to develop their content knowledge of scientific evidence to meet the requirements of recent school curriculum developments which prepare pupils to be scientifically literate. This research reports a replication study in Turkey of an intervention originally carried out with pre-service primary teachers in England. The cohorts had different characteristics; in particular, their overall ability, their confidence in science and how they had been taught science at school were different. Despite these differences the explicit teaching of the "concepts of evidence", which is described, proved to be a targeted and efficient intervention in both cohorts. Following teaching both cohorts had increased their understanding of scientific evidence, improved their ability to conduct an open-ended investigation and they were able to ask questions about the evidence for claims made in a socio-scientific issue. (Contains 9 tables and 2 figures.)