The PERsonal perFORmance in Mammographic Screening (PERFORMS®) selfassessment scheme has been widely used by UK breast screening radiologists. Data obtained from this programme reveal several important factors concerning skill in identifying mammographic abnormalities. These include: those mammographic features which were undetected or misinterpreted by the participating radiologists and any improvement or deterioration in detection ability over the two completed rounds. Areas of individual difficulty have been identified and this information fed back to the radiologists. Training subsets concentrating on these specific features have subsequently been developed. These subsets have been shown to improve radiologists’ cancer detection performance.