Policy-makers and managers use evidence for a range of purposes including making decisions, taking action, developing policy and drafting legislation. It is vital that an indication of the degree of certainty and uncertainty in the evidence is provided.
Past MCCIP report cards have drawn on the IPPCC approach for communicating the degree of certainty in key findings by using a qualitative expression of uncertainty that reflects: (1) the degree of agreement amongst the scientific community; and (2) the amount and nature of the evidence available on which findings are based.
The confidence ratings in MCCIP report cards are assigned by the scientists who provide the evidence for each topic. Although a straightforward process, it has raised challenges when changes in confidence over time are considered. For example, a deeper understanding of a topic (e.g. due to more information being available) can counter-intuitively lead to greater uncertainty and a lower confidence rating.
One way to address such challenges is to manage the expectations of those using the evidence by taking the time to explain what is meant by uncertainty for each topic. This is done by following up any MCCIP reporting with face to face briefings and discussions and by encouraging the use of the more detailed evidence summaries provided for each topic.