[...] This section provides a review of those data integration structures and methodologies relevant to systems biology and to the work described in this thesis. Section 1 describes the three main obstacles facing researchers attempting to integrate systems biology data. Section 2 describes the difference between structuring the integration methodology syntactically and semantically. The methods of integration described in this section can be classified along two axes: firstly, the mapping type (Section 3) determines how the integration interface is connected to the underlying data sources; and secondly, the integration interface (Section 4) determines how the data is retrieved and structured for the end application or user. The implications for the work presented in this thesis and the design decisions made with regard to integration structure and methodology are described in Chapter 5. [...] - Allyson Lister