Modelling memory processes and Internet response times: Weibull or power-law?

The Weibull distribution is proposed as a model for response times. Theoretical support is offered by classical results for extreme-value distributions. Fits of the Weibull distribution to response time data in different contexts show that this distribution (and the exponential distribution on small time-scales) perform better than the often-suggested power-law and logarithmic function. This study suggests that the power-law can be viewed as an approximation, at neural level, for the aggregate strength of superposed memory traces that have different decay rates in distinct parts of the brain. As we predict, this view does not find support at the level of induced response processes. The distinction between underlying and induced processes might also be considered in other fields, such as engineering, biology and physics. (c) 2006 Elsevier B.V. All rights reserved.