Transitions towards sustainability are urgently needed to address the interconnected challenges of economic development, ecological integrity, and social justice, from local to global scales. Around the world, collaborative science-society initiatives are forming to conduct experiments in support of sustainability transitions. Such experiments, if carefully designed, provide significant learning opportunities for making progress on transition efforts. Yet, there is no broadly applicable evaluative scheme available to capture this critical information across a large number of cases, and to guide the design of transition experiments. To address this gap, the article develops such a scheme, in a tentative form, drawing on evaluative research and sustainability transitions scholarship, alongside insights from empirical cases. We critically discuss the scheme's key features of being generic, comprehensive, operational, and formative. Furthermore, we invite scholars and practitioners to apply, reflect and further develop the proposed tentative scheme – making evaluation and experiments objects of learning.

Between 1957 and 1959, Arthur Pardee, Francois Jacob, and Jacques Monod conducted a set of experiments at the Pasteur Institute in Paris, France, that was later called the PaJaMa Experiments, a moniker derived from the researchers' last names. In these experiments, they described how genes of a species of single-celled bacteria, called Escherichia coli (E. coli), controlled the processes by which enzymes were produced in those bacteria. In 1959, the researchers published their results in a paper titled 'The Genetic Control and Cytoplasmic Expression of 'Inducibility' in the Synthesis of b-galactosidase by E. coli'. When they compared mutated strains of E. coli to a normal strain, Pardee, Jacob, and Monod identified the abnormal regulation processes and enzymes produced by the mutated genes. The results showed how enzymes break down the molecules that the bacteria ingested. The PaJaMas experiments uncovered some of the molecular mechanisms that regulate how some genes yield enzymes in many species.

Paul Kammerer conducted experiments on amphibians and marine animals at the Vivarium, a research institute in Vienna, Austria, in the early twentieth century. Kammerer bred organisms in captivity, and he induced them to develop particular adaptations, which Kammerer claimed the organismss offspring would inherit. Kammerer argued that his results demonstrated the inheritance of acquired characteristics, or Lamarckian inheritance. The Lamarckian theory of inheritance posits that individuals transmit acquired traits to their offspring. Kammerer worked during a period in which scientists debated how variation between organisms and within species was caused, and how organisms could inherit that variation from their parents. Kammerer contended that the inheritance of acquired characteristics occurs during embryological development, but several scientists argued that he provided poor evidence for his claims.

Jeffrey Weinzweig and his team, in the US at the turn of the twenty-first century, performed a series of experiments on fetal goats to study the feasibility of repairing cleft palates on organisms still in the womb. Weinzweig , a plastic surgeon who specialized in cleft palate repair, and his team developed a method to cause cleft palates in fetal goats that are similar to clefts that occur in human fetuses. Using their goat congenital model, the team developed a method to repair a congenital cleft palate in utero, or in the womb. The resultant goat newborns had fully developed palates without scarring and with minimal functional impairment. The researchers recommended that surgeons use their repair methods in humans to decrease the incidence of speech impairment commonly associated with cleft palate patients.

Experiments conducted by Elizabeth Blackburn, Carol Greider, and Jack Szostak from 1982 to 1989 provided theories of how the ends of chromosomes, called telomeres, and the enzyme that repairs telomeres, called telomerase, worked. The experiments took place at the Sidney Farber Cancer Institute and at Harvard Medical School in Boston, Massachusetts, and at the University of California in Berkeley, California. For their research on telomeres and telomerase, Blackburn, Greider, and Szostak received the Nobel Prize in Physiology or Medicine in 2009. Telomeres and telomerase affect the lifespan of mammalian cells and ensure that cells rapidly develop within developing embryos.

In 2006, Kazutoshi Takahashi and Shinya Yamanaka reprogrammed mice fibroblast cells, which can produce only other fibroblast cells, to become pluripotent stem cells, which have the capacity to produce many different types of cells. Takahashi and Yamanaka also experimented with human cell cultures in 2007. Each worked at Kyoto University in Kyoto, Japan. They called the pluripotent stem cells that they produced induced pluripotent stem cells (iPSCs) because they had induced the adult cells, called differentiated cells, to become pluripotent stem cells through genetic manipulation. Yamanaka received the Nobel Prize in Physiology or Medicine in 2012, along with John Gurdon, as their work showed scientists how to reprogram mature cells to become pluripotent. Takahashi and Yamanaka's 2006 and 2007 experiments showed that scientists can prompt adult body cells to dedifferentiate, or lose specialized characteristics, and behave similarly to embryonic stem cells (ESCs).