Motivation – This study was conducted to determine how people frame decisions naturally. Research Approach – Decision framing was analyzed in the computer mediated Mars Exploration Rover (MER) mission planning process. Outcomes of proposed actions were coded as positively or negatively framed, with rates of framing compared relative to action specificity and expertise. Findings – It was found that positive framing was preferred in general, and that increased expertise led to more balanced consideration of positive and negative outcomes. Research Limitations/Implications – This study was exploratory and experimentation is necessary to formalize the observed patterns further. Originality/Value – The findings suggest that providing decision-makers additional information about the costs of using technology may more rapidly lead to better mental representations in technology-supported decisionmaking. Take away message – Different kinds of expert behavior promote different patterns of decision framing relative to how technology is used for decision-making.