When listeners judge the loudness of a sound, the responses were shown to depend not only on the stimulus presented on the current trial, but also on stimuli encountered on previous trials. In addition to such sequential effects, order effects are observed in two-interval tasks. For instance, if two identical sounds are presented on a trial, a listener might still judge the second sound to be louder on more than 50% of the trials (time-order error). There is also increasing evidence that one of the observation intervals may receive higher weight in the decision, with consequences for, e.g., the measurement of intensity difference limens. Recent data show that sequential and order effects occur not only in the more traditional tasks used for studying loudness and intensity discrimination, but are also present in temporal perceptual weights. In my talk, I will present some examples for these effects, and will discuss how these effects can be accounted for in the experimental design and in the data analysis.