It is possible to collect data on paper data collection forms and to enter them directly into RevMan. Often, however, there will be a need or desire to manage data in intermediate computer software before entry into RevMan. A variety of software and data management programs may be helpful for this, including spreadsheet software (e.g. Microsoft Excel) and database programs (e.g. Microsoft Access). For example, tabulation of extracted information about studies in a spreadsheet can facilitate the classifying of studies into comparisons and subgroups. Furthermore, statistical conversions, for example from standard errors to standard deviations, should ideally be undertaken with a computer rather than using a hand calculator, since it allows a permanent record to be kept of the original and calculated numbers as well as the actual calculations used.