Software inspections are regarded as an important technique to detect faults throughout the software development process. The individual preparation phase of software inspections has enlarged its focus from only comprehension to also include fault searching. Hence, reading techniques to support the reviewers on fault detection are needed. Usage-based reading (UBR) is a reading technique, which focuses on the important parts of a software document by using prioritized use cases. This paper presents a series of three UBR experiments on design specifications, with focus on the third. The first experiment evaluates the prioritization of UBR and the second compares UBR against check-list-based reading. The third experiment investigates the amount of information needed in the use cases and whether a more active approach helps the reviewers to detect more faults. The third study was conducted at two different places with a total of 82 subjects. The general result from the experiments is that UBR works as intended and is efficient as well as effective in guiding reviewers during the preparation phase of software inspections. Furthermore, the results indicate that use cases developed in advance are preferable compared to developing them as part of the preparation phase of the inspection.