[en] An apparent correlation between the ages and metallicities of field stars, reported in several surveys using ages based on isochrones in the H-R diagram and metallicities based on photometric line-blanketing indices, is shown to be dominated by systematic errors. The sources of error include: the selection of biased samples; age-correlated errors arising from effects of the guillotine and surface gravity on ultraviolet excesses; the small size of any evolutionary trend in metallicity compared to plausible systematic errors in calibration of the indices. Moreover, random errors in photometry lead to systematic errors in age-abundance relations, to such an extent that the whole apparent ''evolutionary change'' of metallicity, between the oldest and youngest disk stars, could arise from random photometric errors of approximately-less-than2 percent