Abstract
In this report, we identify what information is required to support the improvement of existing apportioning tools or the development of new apportioning tools. Such information may be found either in published sources (e.g. peer- reviewed literature) or extracted from databases or other data stores. Here, we list the key information requirements needed to improve, or develop new approaches for, apportioning. Based on this review, we produce a detailed list of data sources that could be used to improve methods for apportioning. We carefully consider the utility of each of these data sources to addressing the key information needs in order to support improvements to the methodologies for apportioning. We assess the strengths and biases associated with each of these data sources. Following this process, we propose which data sources are the most promising and should be taken forward into WP3 for methods evaluation.