Geotechnical instrumentation for monitoring field performance rather than for investigating and determining in situ properties for design is examined in this synthesis. Field performance monitoring commonly includes measurement of pore pressure, earth pressure, deformation, load, and strain. This report addresses key issues that need to be considered when planning and implementing an instrumentation program. The purpose is to provide guidance that will lead to improved cost effectiveness of instrumentation programs.  The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3468