The most important recommendation that must be made is to keep in mind that the purpose of a speech corpus determines the type and design of the corpus. Given a specific aim, one first has to be sure what type of information must be present in the corpus to be collected. Issues to be considered are rather general ones, like the type of recordings (e.g. hi-fi or telephone recordings), but also more detailed ones, like the necessity to collect speech at different hours during the day. In this chapter the type of speech material that can be collected was discussed, running from isolated sounds to spontaneous conversations . In addition, we presented the issues to be considered when the number and type of speakers are concerned.