Abstract: Techniques are described for converting characters that represent a mathematical expression, according to mathematical conventions, into natural language that communicates the mathematical expression based on the rules of the natural language for communicating mathematical expressions. A mathematical expression parser parses the characters representing the mathematical expression into a syntax tree. A visitor function visits each node of the syntax tree and produces natural language for the nodes based, at least in part, on types of the syntax tree nodes and, potentially, contexts of syntax tree nodes. The natural language produced for the syntax tree is assembled into a string based, at least in part, on the structure of the syntax tree. The resulting natural language string may be displayed via a graphical user interface, used by a text-to-speech mechanism to produce a spoken communication of the natural language for the mathematical expression, etc.

Abstract: A method for generating hints for math problems is provided. In response to a request for a hint from a student in a unit of instruction with a scatter plot, shapes are generated based on points in the scatter plot. A convex hull is generated based on the generated shapes.

Abstract: Techniques are described for display and navigation of hierarchical messages, which displays include contextual data for the messages. Context information for a current message includes reply messages, parent messages, and metadata representations. Message representations are also associated with visual depth indicators that are independent of the text of the messages.

Abstract: A method and computer-readable medium for generating an activity stream is provided. The activity stream includes a ranked set of objects that are presented to one or more users. The ranking of objects is updated to reflect events associated with objects.

Abstract: Techniques are described for display and navigation of hierarchical messages, which displays include contextual data for the messages. Context information for a current message includes reply messages, parent messages, and metadata representations. Message representations are also associated with visual depth indicators that are independent of the text of the messages. Users may navigate displays of hierarchical message data using different navigational inputs. For example, more information may be requested for messages, without selecting a new message for viewing as a focal message, using swipes across portions of the display dedicated to displaying the messages. A limited number of messages for a requested list of messages is initially retrieved and displayed, and a mechanism for viewing more messages from the list is provided. Historical usage of the mechanism is recorded and the number of messages to be displayed for the list of messages is adjusted based on the historical usage data.

Abstract: A method includes analyzing a first document to identify a first set of one or more tags and responsive to identifying the first set of one or more tags: automatically producing a second document based in part on first set of one or more tags, where the second document includes one or more accessibility features that were not in the first document.