Course Content


7 - Total Error



Total error (TE) combines bias and imprecision to quantify the largest variation from the true (target) value.  In this activity, participants are introduced to bias and true value.  Using the information supplied by 3 key numbers, participants calculate the TE in units and percent.  Additionally, participants explore the impact that bias and imprecision can have on TE and relate site-specific processes that affect TE to checklist items.

Key Message

  • 3 key numbers are required to calculate TE – mean, SD, and true value.
  • The target value is our best estimate using sources that each has its own limitation.
  • TE is the total variation of our value from the true value.

Self Assessment

Can you: 

  • Calculate bias and absolute bias?
  • Calculate TE in units and percent?
  • Identify ways to reduce bias and imprecision at their site?