Table 2.

Scoring system method and classification examples according to the animal-centered research framework.

Score	Relevance	Impartiality	Welfare	Consent
5	Procedure is relevant for partakers	Individuals receive highest consideration regardless of their capacities	Procedure enhances partakers’ welfare	Partakers are enabled to choose whether and how to engage with procedure
e.g., Using a drug to reduce participants’ existing disease symptoms	Partakers already suffer from a spontaneously occurring disease and the trial is set to benefit them individually and directly	Partakers receive a high standard of care, they are allowed to freely express and meet their physical, behavioral and emotional needs at any time	Experimental setting improves the living conditions of partakers compared to standard living and housing conditions (e.g., providing housing with no height differences, stairs or slopes for animals with impaired mobility)	Partakers are allowed to choose between different medicated or unmedicated foods and their spontaneous response is recorded
4	Procedure is relevant for partakers but benefits may not be direct or immediate	Individuals receive high consideration but not as much as others with more capacities would	Procedure does not impact negatively on partakers’ welfare	Partakers are mostly able to choose whether and how to engage with procedure
e.g., Testing several painkiller drugs to identify the most effective one	Partakers suffering from a painful condition may or may not benefit from the trial depending on which painkiller they receive but findings are set to benefit the species and all partakers in future	Partakers receive a good standard of care, some aspects are not properly considered (e.g., poor enrichment) because they are thought to be irrelevant for the species or for the duration of the trial	Animals receive a standard level of housing and care; their welfare is not affected by experimental procedures	Some procedures/sessions are scheduled to assess painkillers’ effect (including animal manipulation and samples collection) but partakers can decide when to stop them
3	Procedure has some relevance for partakers but benefits are only indirect and only in future	Individuals receive some consideration but notably less than more capable ones would	Procedure has minor negative impact on partakers’ welfare	Partakers have limited ability to choose whether and how to engage with procedure
e.g., Testing promising experimental drugs in vivo for the first time (effects on the species are not entirely known)	Partakers may be harmed during the trial, and they and their species may never benefit from the research findings	The standard of care is poor, some aspects are lacking (e.g., enrichment, social contact) because they are thought to be irrelevant for the species	Partakers experience minor discomfort of short duration due to the procedures	Partakers are trained to sit or to stand still for a blood drawing because they will receive a treat afterwards
2	Procedure has little relevance for partakers and benefits are only indirect and only in future	Individuals receive significantly less consideration than more capable ones would	Procedure has significant negative impact on partakers’ welfare	Partakers are mostly not allowed to dissent or withdraw from procedure
e.g., Testing a drug intended for another species but which may be used in the future also in the partaking species	Partakers are unlikely to benefit from the research findings but are likely to suffer harms during the trial, even though their species might benefit in future	The standard of care is low but animals are checked for signs of poor welfare	Partakers are likely to experience moderate discomfort or pain during the procedures	The procedure (e.g., blood drawing) is carried out unless the animal shows signs of distress
1	Procedure has no relevance whatsoever and no benefits for partakers even indirectly or in future	Individuals receive very little or no consideration compared to more capable ones	Procedure has severe negative impact on partakers’ welfare	Partakers are not allowed to dissent or withdraw from procedure in any way
e.g., Testing the toxicity of a drug for human use	Partakers are knowingly harmed during the trial and will never benefit from the research findings	A minimal standard of care is adopted because animals are deemed incapable of experiencing discomfort or pain	Partakers are likely to experience severe and prolonged discomfort or pain during the procedures	Partakers are restrained and the procedure is carried out as programmed