Social systems are changing so rapidly that it is important for humans to make decisions considering uncertainty. A scenario is information about the series of events/actions, which supports decision makers to take actions and reduce risks. We propose Action Planning for refining simple ideas into practical scenarios (strategic scenarios). Frameworks and items on Action Planning Sheets provide participants with organized constraints, to lead to creative and logical thinking for solving real issues in businesses or daily life. Communication among participants who have preset roles leads the externalization of knowledge. In this study, we set three criteria for evaluating strategic scenarios; novelty, utility, and feasibility, and examine the relationship between externalized knowledge and the evaluation values, in order to consider factors which affect the evaluations. Regarding a word contained in roles and scenarios as the smallest unit of knowledge, we calculate Relativeness between roles and scenarios. The results of our experiment suggest that the lower the relativeness of a strategic scenario, the higher the strategic scenario is evaluated in novelty. In addition, in the evaluation of utility, a scenario satisfying a covert requirement tends to be estimated higher. Moreover, we found the externalization of stakeholders may affect the realization of strategic scenarios