Four experiments that examine the relationship between the rated truth of statements and prior study of parts of those statements are reported. The first 2 experiments show that new details about familiar topics are rated truer than new details about unfamiliar topics. Recognition of a topic as familiar disposes subjects to accept new details as true. The 3rd and 4th experiments show that statements initially studied under an affirmative bias are rated truer than statements originally studied under a negative bias. Since even the negatively biased statements are rated truer than new ones, subjects are not remembering the bias. Rather, different biases during study affect the probability that details will be encoded into memory. In contrast to differential biases, different study processes affect the likelihood that subjects will remember having studied the statements, but do not affect truth. The results are discussed in terms of the hypothesis that remembered factual details are the criterion of certitude against which tested statements are assessed.