In this chapter, I want to return to the question of the nature and reach of impact, the third dimension of impact covered in this book. The focus in the sub-panels included in this book is on changing policy, discourse or practice. Although there are some collaborations with the private sector, in the main the intended change is taking place at the policymaking and practitioner level (see also Bastow et al, 2014). The previous chapter compared the ICS based on a number of indicators, and also highlighted particular themes such as technical contributions, big, interdisciplinary problems such as climate change, issues of timing and attribution being accommodated in the case studies. The list is not exhaustive, as I did not examine all the case studies submitted to the three sub-panels. The similarities and differences between the submissions are likely to reflect nuances of disciplinary differences that are missed in comparisons of a larger number of disciplines such as in the work by Bastow et al (2014) and King's College and Digital Sciences (2015). The second step is to bring together the different analytical lenses and develop a comprehensive typology of impact.

While the academic community is familiar with peer review of publications, evaluating impact of academic work on this scale is still in its infancy and only a few studies exist that have tried to develop a typology and ranking of impact (these are Morton, 2015a; 2015b; Smith and Stewart, 2016). Based on interviews with Social Policy academics regarding their view of the inclusion of impact in the REF2014 and a brief analysis of the highest and lowest ranked ICS submitted to the Social Policy and Social Work panel, Smith and Stewart (2016) have developed an impact ladder that places the highest importance on ideas in terms of reach and significance. Therefore, at the top of the impact ladder sits influencing the overall framework or paradigm of how an issue is perceived. This is followed by contributing to establishing an issue, influencing how a particular aspect of an issue is perceived, assisting policymakers in making incremental changes, and, finally, providing support for existing policies, including commissioned research (Smith and Stewart, 2016: 118, Figure 1). The authors further argue that the degree and significance of impact moves in the opposite direction to the ability to demonstrate said impact.