The Three Vs have been proposed by Professor Hanno Würbel (2017):

• Construct Validity - the level of agreement between the animal model, test or outcome variable and the quality it is meant to measure
• Internal Validity - the scientific rationale (e.g. use of appropriate control groups) and scientific rigor (measures against risks of bias)
• External Validity - experimental design features that enhance, or facilitate inference about, the reproducibility and generalizability of the expected results

Webinar by Hanno Würbel (10 November 2021): Making a case for animal research: The 3Vs and 3Rs principles

References

• Würbel (2017): More than 3Rs: the importance of scientific validity for harm-benefit analysis of animal research
• Eggel & Würbel (2021): Internal consistency and compatibility of the 3Rs and 3Vs principles for project evaluation of animal research
• The 3Rs principle