1. A system comprising: at least one processor and executable instructions accessible on a computer-readable medium that, when executed, cause the at least one processor to perform operations comprising: receiving a selection, over a network from a client machine, the selection identifying a filter from a first plurality of filters, the filter including a first attribute-value pair, the first attribute-value pair including a first attribute and a first value, the first attribute-value pair being included in a concept query that was extracted from a query including at least one keyword that was received over the network from the client machine; and identifying a second plurality of filters responsive to receipt of the selection, the identifying of the second plurality of filters being based on the first attribute and probabilities describing occurrences of attribute-value pairs in a plurality of listings respectively describing items that were previously transacted on a network-based marketplace, the second plurality of filters including a plurality of values; generating a user interface including the plurality of values and search results that are identified based on the concept query; and communicating the user interface, over the network, to the client machine.