Early in its path, forecasting Erika's motion was difficult, with a persistent leftward bias in official forecasts.

Studies show that this has led to a persistent bias among published clinical trials in drug companies' favor.

Dr. Leeman has been a vocal critic of what she says is persistent bias against women in science at every stage of their careers.

He insists that size, not race, was the source of the most persistent bias he faced.

They argue that "small differences in performance in the NAEP and other studies receive extensive publicity, reinforcing subtle, persistent, biases."

And so the Guardian/Observer's persistent anti-Amazon bias continues.

Their volatility is troublesome, but that by itself does not cause a persistent bias one way or the other.

This study, funded by the National Institutes of Health is another example of persistent bias against including women in N.I.H. research where the outcome may apply to both sexes.

Unlike sampling errors, they can cause persistent bias in measurements of the index.

And this leads to my point: once again we are reminded of a persistent bias in American education that it is acceptable to have poor math skills.