"To join the trial" means becoming a participant in an experiment or test. It refers to getting involved in a study or investigation to help gather data, learn more about something, or contribute to finding a solution. Full definition
Dina Asher - Smith, who was pipped to the British 60m title on Saturday, will join trials winner Asha Philip in Portland. (athleticsweekly.com)
«There are an increasing number of patients who are co-authoring academic research papers, co-designing trials and studies, and joining trial management teams,» Stephens says. (sciencemag.org)