Lexicographic heuristic refers to when a consumer chooses the best brand on the basis of its perceived, most important attribute.
Further discussion on lexicographic heuristic:
As a side note, heuristic, in this case, refers to a rule of thumb in a consumers decision-making process. The expectancy-value model (a compensatory model) states that a products (or services) perceived good qualities (things) can help overcome perceived bad things. However, consumers often take a mental shortcut (heuristics) to make a buying decision.
The lexicographic heuristic is one of three choice heuristics a consumer may use to make a buying decision.
Example of lexicographic heuristic:
As an example, a consumer may be faced with the need to buy a smartphone. Given that the available smartphone brands are equal in the consumers mind, the consumer will select a smartphone based on its perceived important attribute. This could be that one particular smartphone, over the other options, may have a perceived better camera or user interface.