This paper reports on a one day field validation exercise that took place in the context of the 2016 Canadian Space Agency-led Mars Sample Return Analogue Deployment. Here, a “human” field team using traditional geological methods was given the same objective as the rover-based remote science operations team: to select the sample within the site with highest total organic carbon content as a proxy for signs of life. While the exercise, by design, was limited in operations time, a comprehensive data set was assembled related to decision-making, comprising detailed daily reports and logs produced by the remote science operations team, and a continuous voice recording and GPS track for the field team. Summaries of these data are tabulated in this report. These data enabled a direct comparison of the data developed by each team, and the decisions they took, leading to an assessment of both accuracy (effectiveness of task completion) and efficiency (time for task completion). This paper reports: (1) the surprising speed (15 min) at which the field team established basic stratigraphic relationships, (2) the relative effectiveness with which the field team identified and visually tracked indistinct bedding features, and (3) challenges related to assessing scientific success in a geological field setting, highlighted by differences in the stratigraphic sections produced by the two teams, and the detection of a ‘marker’ bed by the field team and not by the remote science team. As primary conclusions, we note that (1) this exercise has demonstrated higher efficiency a factor of around 50 times for a human team compared to a remotely operated rover - for scientific discovery tasks conducted across a relatively simple, gently undulating, 200 m × 200 m terrain, and (2) the results broadly support the concept of walkabout as an effective strategy for robotic planetary exploration (Yingst et al., 2018, and references therein) with a specific finding related to mapping stratigraphic relationships. We also discuss the value and shortcomings of this validation approach and provide lessons learned and recommendations for the design of future analogue mission exercises.