When engaging in some behaviour, some actions by an animal are more likely to resonate with us as observers than others and those impressions often form the basis for the behavioural markers that we choose for measurement. However, as much as possible, we should view the context from the animal’s perspective as it is what is important to them that guides their behaviour. Of what the animal may be able to sense, some sensations rank as perceptions that are relevant to the animal in that context. Moreover, in dynamic situations, it is often those perceptions that the animal seeks to stabilise. This means the behaviour controls those perceptions, so many actions can be explained as being compensatory. Without knowing what an action is compensating for, actions may be mistakenly abstracted as markers to measure. So, the first principle is to identify the perceptions that are relevant to the animal.