(Q) = PriorityD (D) * X2 + PriorityU (U) * X + PriorityQ (Q)
where PriorityD (D), PriorityU (U), and PriorityQ (Q) are the domain, users,
and query priorities. As a result of this step we obtain a set of queries ordered
by priority. The form QRY_USR is updated in order to complete the Global
priority field. These priorities are a tool for solving conflicting requirements.
For example, in our case study, query Q1 has priority 5 for user U2 (with priority
1), who belongs to domain D1 (with priority 5). Thus, the global priority
for query Q1 is 135.
??? Data.requirements.matrix: This is the integrated requirements form. This
form is used for exchanging information with data producer users. The form
MAT_REQ_DATA is filled out.
Example 4: Figure 1 shows a portion of the form MAT_REQ_DATA for
our case study. Each triple domain-user-query has associated with it a set
of data quality dimensions and values for these dimensions. Note that this
form summarizes information obtained during the previous phases.
Phase.IV:.Data.Source.Selection
In this phase, data sources are studied in order to determine if they fulfill the information
requirements collected in phases I to III. The outputs of the phase are (1) a
query evaluation report and (2) a data source selection order for each data element.
This process is central to our methodology. As far as we are aware of, this is the
8 Vaisman
Copyright ?© 2007, Idea Group Inc.
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