Data Preparation User Interface with Conglomerate Heterogeneous Process Flow Elements

A method prepares data for analysis. The method displays a user interface, which includes multiple panes, including a data flow pane. The data flow pane includes a flow diagram having multiple nodes, each specifying a primary operation and/or multiple secondary operations. Each primary operation retrieves data from a data source, transforms data, or builds an output data set. When a user selects a node, the user interface displays a change list pane, which is an ordered list of secondary operations performed at the node. When the user provides input to perform a secondary operation at the selected node, the user interface (i) performs the secondary operation, (ii) updates the selected node with an indicator that the node includes secondary operations, (iii) determines a logical ordering for the secondary operation based on the primary operation, and (iv) adds the secondary operation to the change list pane according to the logical ordering.