1 INTRODUCTION

The growth of risk assessment and risk-based models in preventive conservation has been considerable over the last 10 years (Waller 2002), making conservation planning a more rational process (Waller 2003). Risk assessment—the evaluation of potential damage from identified hazards to collections—is an extremely useful concept for preventive conservation and planning because it does not rely on the existence of damage to establish priorities for its prevention. Risk management—the generation, selection, and implementation of options to accept, reduce, or change risks—requires information that has a rational framework, such as risk assessment, to evaluate and select appropriate options for the preservation of cultural heritage. Waller states that “forecast risk, rather than measured damage to cultural property, is the appropriate measure to manage the preservation function of a museum. Measurement of collection condition over time will provide verification (or not) of the efficacy of the preservation function but not by itself provide sufficient information to monitor or plan the preservation function” (Waller 2002, 102).

Collection condition cannot be used to predict the future, but using more than one perspective, such as including empirical information about condition, can give perception of risk greater depth and clarity. For example, when exposure to a risk is identified but the collection is stable, or objects are deteriorating within accepted levels, resources could be spent on resolving issues that are not affecting the collection as much as other risks. Although intersurveyor differences may be the root of some of this discrepancy, the forecasting of damage and the behavior of objects can highlight where that discrepancy is (regardless of the reason) and illustrate areas that may need further analysis. In some cases, empirical information, such as collection condition, can refine this assessment. Introducing concepts of perception to risk assessment can help integrate such information. This article looks at visual perception as an analog to inferring from risk and condition assessments, since it provides more information than any of the other senses (Eysenck and Keane 2000). Cognitive psychologists and philosophers of science investigating decision making have drawn analogies with the key principles of visual perception (e.g., Tversky and Kahneman 1974; Oaksford and Chater 1998; Chalmers 1999). However, this article is not intended to be a review of the visual perception field.