<aside> 🚩 A situation is a description of a group of entities and their interactions from a point of view external to the entities and their interactions.
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A situation is a model of reality, created as objectively as possible, and intended to document everything that is relevant to achieve your design goals.
Using situations in decision-making is not limited to design; this approach can be used in law, medicine, all analytic engineering tasks, etc. The specific application of situations to design is covered under the topic of Situation Scans.
The goal of designing is to improve the way things are. We cannot improve how things are if we don't understand deeply how they actually are. That's what design situations are for; they are the baselines from which we can measure progress. You can't measure anything without an origin - a "zero point" - from which to measure.
Another way of thinking about this is: to be meaningful, designing must be grounded in some real-life conditions. The less concrete the conditions for which one designs, the less likely that the design intervention will improve things. So the best design interventions will be those that are firmly rooted in real-life conditions.
Say you're designing a way to temporarily bind sheets of paper together quickly, easily, and economically. Here are some of the questions you'd have to answer before starting to design a new product.