The principle of`divide and conquer' (DAC) suggests that complex decision problems should be decomposed into smaller, more manageable parts, and that these parts should be logically aggregated to derive an overall value for each alternative. Decompositional procedures have been contrasted with holistic evaluations that require decision makers to simultaneously consider all the relevant attributes of the alternatives under consideration (Fischer, 1977). One area where decompositional procedures have a clear advantage over holistic procedures is in the reduction of random error (Ravinder, 1992;Ravinder and Kleinmuntz, 1991;Kleinmuntz, 1990). Adopting the framework originally developed by Ravinder and colleagues, this paper details the results of a study of the random error variances associated with another popular multi-criteria decision-making technique, the Analytic Hierarchy Process (AHP); (Saaty, 1977(Saaty, , 1980, as well as the random error variances of a holistic version of the Analytic Hierarchy Process (Jensen, 1983). In addition, data concerning various psychometric properties (e.g. the convergent validity and temporal stability) and values of AHP inconsistency are reported for both the decompositional and holistic evaluations. The results of the study show that the Ravinder and Kleinmuntz (1991) error-propagation framework extends to the AHP and decompositional AHP judgments are more consistent than their holistic counterparts. Copyright # 2001 John Wiley & Sons, Ltd. key words random error reduction; Analytic Hierarchy Process; holistic decompositional decisionsMost decisions in everyday life involve multiple attributes. A central concern of decision analysis is the evaluation of multiple attributes in the process of resolving such decision problems. Keeney and Raiffa (1976) argued that complex multiattribute problems can be solved through a decompositional approach that relies on the principle of`divide and conquer'. First, the complex problem should be broken down into smaller parts. Next, judgments are performed on these smaller parts. Finally, these simpli®ed judgments are aggregated to derive a score for each stimulus and the highest-valued alternative (or option) is selected as the best course of action.Copyright # 2001 John Wiley & Sons, Ltd.ÃCorrespondence to: Osvaldo F. Morera, Department of Psychology, University of Texas at El Paso, El Paso, TX 79968, USA. E-mail: omorera@utep.eduDecompositional techniques have been contrasted with holistic evaluations that require the judge to simultaneously consider all relevant attributes in the decision problem. Although it has been shown that individuals can perform holistic evaluations when the number of attributes and alternatives is small (Slovic and Lichtenstein, 1971), Fischer (1977) criticized holistic decision making on the grounds that it contains large amounts of random error. This sentiment has been reiterated by Kleinmuntz (1990), who speculated that the consistency of holistic judgments should deteriorate because of limits on huma...