The decays of the 2p J=1/2 and J=3/2 levels of Li-like ions and of the 2s2p 1,3Po1 levels of Be-like ions can be used as simple-atom test beds for lifetime measurements and for the development of accurate calculations of the transition rates. We have summarized and filtered the experimental data in order to obtain consistent data sets and isoelectronic trends that can be compared to theoretical predictions. The graphical presentation of line strength data enables direct comparison and evaluation of the merit of data along extended isoelectronic sequences. From this, the precision that is necessary in future meaningful experiments can be deduced.