Technology Transfer SSC Pacific
Advanced Hooking Algorithm (AHA)

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A method and apparatus for enhancing a computer user's selection of objects displayed on the user’s computer screen

The U.S. Navy seeks to commercialize U.S. Patent 5,757,358 (Method and apparatus for enhancing computer-user selection of computer-displayed objects through dynamic selection area and constant visual feedback).


Current user-interface designs typically require an end-user to place a cursor directly on an object to be selected. These designs only provide feedback after the user performs an action to select the desired object. The Advanced Hooking Algorithm (AHA) supports and enhances existing user-interface designs by providing constant computation of a “selectable” cursor target, which is the object closest to the current cursor position on a computer display.

The Technology

When using AHA, the distance to all display symbols is computed in real time as a cursor is moved. The effective object selection area is increased without enlarging the displayed size of either the object symbology or cursor. The system identifies the “selectable” object by providing a visual indication of the closest object to the cursor before a user selection action is made. This provides a vast improvement over current designs where object symbols are small, closely clustered, or overlap.

Key Benefits

  • Improves object selection speed and accuracy
  • Reduces required cursor travel distance to an object
  • Improves track selection and information retrieval with trackball, mouse, touch-tablet, and all other input devices by a factor of two to three
  • Provides real-time computation that is dynamic, not static based on initial design
  • Works over all software platforms and displays (including mobile-based)
  • Has no impact to machine performance for any number of objects
  • Development Status

  • U.S. Patent issued: 5,757,358
  • DoD 5000 Series Technology Readiness Level 7: System prototype demonstration in an operational environment
  • Implemented for several military user-interface systems
  • Field test data results available
  • For more information on technology transfer, please contact us at (619) 5535118 or email   
    SD 612, September 2005. SSC Pacific, San Diego, CA 921525001. Approved for public release; distribution is unlimited.

    SSC Pacific
    Updated: 11/8/2011 2:42 PM EST   Published