Exploratory methods begin from the present, and see where events and trends might take us; normative methods begin from the future, asking what trends and events would take us there.
A fundamental distinction in futures and forecasting studies is commonly drawn between exploratory and normative methods. This terminology is well-established, but rather misleading (since both approaches involve exploration, of course, and both call into play questions about norms and values).
Exploratory methods are "outward bound". They begin with the present as the starting point, and move forward to the future, either on the basis of extrapolating past trends or causal dynamics, or else by asking "what if?" questions about the implications of possible developments or events that may lie outside of these familiar trends. Trend, impact, and cross-impact analyses, conventional Delphi, and some applications of models are among the tools used here. The majority of forecasting studies are mainly exploratory, though when these result in alarming forecasts, there may well be an effort to locate turning points or policy actions that could create a more desirable future.
Normative methods are, by contrast, "inward bound". They start with a preliminary view of a possible (often a desirable) future or set of futures that are of particular interest. They then work backwards to see if and how these might futures might or might not grow out of the present – hot they might be achieved, or avoided, given the existing constraints, resources and technologies.
An common example of a desirable future that can sustain a normative approach is the Knowledge Society envisaged in the European Commission's Lisbon strategy.
The tools used here include various techniques developed in planning and related activities, such as morphological analyses and relevance trees, together with some uses of models and some less conventional uses of Delphi such as "goals Delphi" methods. A fairly recent development is the use of "success scenarios" and "aspirational scenario workshops", where participants try to establish a shared vision of a future that is both desirable and credible, and to identify the ways in which this might be achieved.
What is the right mix?
There is little evidence as to when each of these approaches is most valuable, and again in practice we often find Foresight involving a mixture of the two. It may be that more normative approaches are most likely to be effective where a widely shared goal already exists, and where Foresight can then help put flesh on the bones of this implicit vision of the future. For example, a common long-term regional goal may be for more rapid and equitable economic development in the region; or where S&T issues are at stake, it may be to achieve a secure grip on at least some niches of technology innovation, production and use. In such cases, normative approaches can be powerful inputs into priority-setting and other elements of decision-making (and help provide road-maps and indicators that can be used to monitor progress towards the desired future). In other cases, normative approaches may be considered insufficiently objective, or there may be a lack of consensus as to shared goals, at least in early stages of the Foresight process. Exploratory methods can then be expected to predominate.