Recent Webinar Q&A on Formative vs Summative Evaluations:

QUES:  About Usability studies : could you explain why formative report is a verification data whereas summative report is a validation data ? Indeed, we considered both documents as verification data for the validation of the instruction for use.

ANS:  I stressed that I use my "working definitions" and that you should develop the same (defined in your SOPs and FOLLOWED); that regulatory agencies give much leeway on definitions as long as they are reasonably covered by ISO / GMP, etc., definitions.

RE:  Formative and summative (per IEC 62366), see FDA Guidance "Applying Human Factors and Usability Engineering to Medical Devices", Guidance, dated February 3, 2016,

page 3, Definition "3.3 Formative evaluation Process of assessing, at one or more stages during the device development process, a user interface or user interactions with the user interface to identify the interface’s strengths and weaknesses and to identify potential use errors that would or could result in harm to the patient or user. " I defined as testing, checking  ... verification;

page 20, footnote 4:  "4 Human factors validation testing is sometimes referred to as “summative usability testing.” However, summative usability testing can be defined differently and some definitions omit essential components of human factors validation testing as described in this guidance document."

Further response to the first question:

 

QUES: Could you explain why formative report is a verification data whereas summative report is a validation data ? Indeed, we considered both documents as verification data for the validation of the instruction for use. 

 

ANS:  You are correct when you state that both your formative evaluations and summative evaluation would be verifications as part of the validation of the IFU.  This is because both are used for another step, that is, the validation of another entity, not the UE / HF device interface. Clarify in the SOP. 

 

However, my above comments are based on UE / HF applications , where formative evaluations/testing are in-process verifications of UE/HF, and summative evaluation is the final validation of the device design interface.  Where those documents satisfy the definitions of formative and summative in evaluation of a device's user interface, if they are used for another application / entity, e.g., IFUs, then both could be considered verifications / tests which become part of the IFU validation.

-- jel@jelincoln.com   

In summary, in general "formative evaluation" is in-process testing, inspections, checking, or what I generally define as a "verification" (but in this case it can also be a verification of several requirements rather than just one), and a "summative evaluation" is the final sum total of a series of final "verifications" combined into the end-stage "validation".  Check this "working definition" against the appropriate ISO or CGMP definition(s) (which also suffer from some ambiguity) to work up your company's own "working definitions" for your SOPs, then follow your SOPs! In several decades in this industry, I have never seen an FDA CSO or Notified Body Inspector raise an issue with reasonable "working definitions" used by a company to add meaning / local / company explanation to a formal ISO or CGMP, et al, term to further better understanding / compliance by an operator, etc., if it's reasonable / "in the ball park" as to intent / meaning, addresses the principle in the formal definition. - JEL, 08/14/2025