Having looked at the idealised but impractical compensatory rule we now consider the more commonly used lexicographic rule.
The agent making a decision will list the attributes of the objects under consideration. Suppose for example the agent is buying a mattress; the list of attributes would comprise of comfortability, price, brand name, delivery and return policies, and appearance. The agent will then prioritise the attributes, which is similar to weighting in compensatory decisions. This can be done loosely so long as the subject has a sense of what is more or less important. In this case let’s say that top priority is comfort, second is price, and third is the return policy.
The agent then assesses each option based on the top attribute and selects the best. In the case of a tie the next most important attribute is compared, and this occurs iteratively until there is a distinguishing factor between attributes. In the case of the mattress our agent cares most about comfort, and thus which ever is the most comfortable will be purchased. If 2 mattresses are of equal comfort the subject will compare them based on price and buy the cheaper one. If they are equivalent in price the return policies will be compared, and so on.