Evidence to Explain

Evidence to Explain (EE) includes the actions, events, behaviours, and so forth that inspire an investigation. Typically, a key piece of evidence will have stood out against our expectations, and this we will call indispensable evidence.

The way we characterise indispensable evidence is crucial to framing good investigations. Following the previous example, if Charlie says “my tooth hurts”, we might characterise that evidence as “Charlie’s tooth hurts”, or we might say “Charlie says that his tooth hurts”. These are importantly different.

In the first case, we assume that Charlie’s tooth does, in fact, hurt. We assume that Charlie is not telling stories, or that something other than his tooth hurts, but that he feels it in his tooth. Characterising the evidence as though there is no question that his tooth hurts focuses the investigation in a certain way.

In the second case, we do not assume that Charlie’s tooth actually hurts, which opens our investigation to the possibility that he’s telling stories, or some other explanation. The questions we frame to address this evidence, as suggested in the previous section, differ from the questions we frame to address differently-characterised evidence. In either case, it is worth pausing to consider the effects of how we characterise evidence, given the circumstances under which our investigation has arisen. This demonstrates the tight relationship between framing of evidence and lead questions.

Importantly, the kind of evidence we want to make explicit is evidence to explain. We need to craft questions in such a way that their answers will tell a good story about why the action, event, behaviour in question came about.

In either case, answers to lead questions explain evidence. Therefore, the relationship between answers and evidence is as tight as that between evidence and lead questions. The choices you make in framing any and all of this can dramatically affect the explanations you come up with, and the overall quality of the inference.

Again, if we characterise Charlie’s complaint as “Charlie has a sore tooth”, this characterisation points the investigation in a certain direction. If we characterise Charlie’s complaint as “Charlie complains of a sore tooth”, the investigation can take a different turn. In this latter case, we might explain the complaint as “Charlie doesn’t want to go to school”, which is not an available explanation when investigating why his tooth hurts (assuming it does).

This sort of distinction often plays a role in evaluating the results of scientific experiments: do we wonder why the temperature of the metal is 100 degrees, or do we wonder why the thermometer reads 100 degrees? If we say the temperature is 100 degrees, then we exclude talk of miscalibrated thermometers.

Generally, we must characterise the evidence consistently with our framing of the investigation. Unless you’re quite certain of testimony or the precision and accuracy of equipment, when characterising evidence, it is a good idea to avoid “is”-formulations; hedging with “appears” or “seems” can make a wider range of explanations available. How much to hedge will, as always, depend on your judgement.

Last modified: Wednesday, 7 February 2018, 9:39 PM