This paper presents a qualitative study that investigates the effects of some language choices in expressing the trigger part of a trigger-action rule on the users' mental models. Specifically, we explored how 11 non-programmer participants articulated the definition of trigger-action rules in different contexts by choosing among alternative conjunctions, verbal structures, and order of primitives. Our study shed some new light on how lexical choices influence the users' mental models in End-User Development tasks. Specifically, the conjunction "as soon as" clearly supports the idea of instantaneousness, and the conjunction "while" the idea of protractedness of an event; the most commonly used "if" and "when", instead, are prone to create ambiguity in the mental representation of events. The order of rule elements helps participants to construct accurate mental models. Usually, individuals are facilitated in comprehension when the trigger is displayed at the beginning of the rule, even though sometimes the reverse order (with the action first) is preferred as it conveys the central element of the rule.

翻译：本文通过定性研究探讨了触发-动作规则中表触发条件的语言选择对用户心智模型的影响。具体而言，我们研究了11位无编程经验的参与者在不同场景下通过选择不同连词、动词结构和基元顺序来定义触发-动作规则的过程。研究揭示了词汇选择如何影响最终用户开发任务中的用户心智模型的新见解：连词"as soon as"明确支持瞬时性概念，而"while"则体现事件的持续性；但最常用的"if"和"when"反而容易在事件的心理表征中造成歧义。规则元素的排列顺序有助于参与者构建准确的心智模型。通常将触发条件置于规则开头有助于理解，尽管有时逆向顺序（动作前置）更受欢迎，因其能突出规则的核心要素。