A value is the data found in a field. In a field called {customer.CONTACT FIRST NAME}, for example, John or Mary might be the value. In a field called {orders.ORDER AMOUNT}, 1234.55 or $200 might be the value.
Variance is the square of the standard deviation. It is a measure of the amount by which all values in a group vary from the mean (average) value in the group. It is a statistical test that can be used to evaluate the variability in a group of values (for example, the amount bid by each of the bidders on a construction project).
Variance (as opposed to PopulationVariance) is most often used to project the variance for an entire population (all values) based on testing only a small sample of that population. For example, with a limited number of bids in on a construction project, you might want to project the variance for all bids based on the sample already in. Or, based on sales figures for the first three months of the year, you might want to project the variance for orders for the entire year (including the nine months yet to come).
Note: These comparisons simply suggest typical usage. In practice, some users prefer a calculation based on N values (PopulationVariance) while others prefer a calculation based on N
In Crystal Reports terms, verify does not mean to repair and compact the database (MDB file) in Access. It means to let the report understand the changes made to the database structure (fields and tables, NOT records).
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