In 1994 Douglas Altman wrote a highly influential paper in the British Medical Journal entitled ‘the scandal of poor medical research’. It focused on the prevalence of poor design and analysis in medical research, due to a general failure to appreciate the principles underlying scientific research. Addressing these shortcomings would entail better science education, not only of researchers, but also of the public and judiciary. But there is another factor at work; ‘confirmation bias’. This is probably the most widespread and insidious form of bias, where scientists search much harder for evidence to support their pet idea than for evidence to refute it – and weight that evidence accordingly. To show that such matters are not merely of academic interest, two recent examples are considered.