1. A computer device, comprising: a processor; and a data visualization tool configured to display data items of a data set in a graph and display a query panel associated with the graph, the query panel including one or more data entry fields to receive queries regarding properties of one or more specific data items in the graph relative to a target data item, the data visualization tool further configured to, in response to a user-entered query on the query panel regarding a visually unrepresented property of the specific data items displayed in the graph relative to the target data item, assign a discrete value selected from a continuous range of analog values to represent the visually unrepresented property returned by the query, and add an analog representation of the discrete value selected from the continuous range of analog values to represent the visually unrepresented property returned by the data query into the displayed graph of the data items, wherein the query panel includes at least one input element for selecting one or more pre-defined queries, the one or more pre-defined queries including a pre-defined query having a degree of similarity between the data items relative to the target data item as a query parameter, and wherein data items which have a queried degree of similarity to the target item with respect to an implicit property of the data items are identified on the displayed graph upon submission of the pre-defined query for processing.