THE celebration of Mary MacKillop's miracle cancer cures is a worrying example of the lack of scientific literacy in the community, says an expert in evidence-based medicine.

The question is not whether the NSW mother Kathleen Evans recovered from her cancer after praying to MacKillop but how many others prayed and did not go into remission, said Chris Del Mar, a professor of primary care research at Bond University.

Professor Del Mar said popular acceptance of MacKillop's miracle was part of a wider problem of people not understanding scientific and mathematical methods, exemplified by newspapers printing horoscopes and people using alternative medicines that had little evidentiary support.

"These things betray a false thinking that is not limited to Mary MacKillop or religion," Professor Del Mar said.

Research had also shown people were more likely to take notice of things which supported their beliefs.