Averaging the estimates of a number of individuals has been shown to produce an estimate that is generally more accurate than those of the individuals themselves. Similarly, averaging responses from a single individual can also lead to a more accurate answer. How can we best combine estimates within and between individuals to create an accurate group estimate? We report empirical results from a general knowledge rank-ordering experiment and demonstrate that individuals that provide more consistent answers across repeated elicitations are also more accurate. We develop a consistency weighting heuristic and show that repeated elicitations within an individual can be used to improve group accuracy. We also develop a Thurstonian cognitive model which assumes a direct link between the process that explains the accuracy of an individual and response consistency and show how the model can infer accurate group answers.