In this 2-minute video, ESS Deputy Director Diane Kennedy talks you through the TREBL framework which can help you think about ‘good enough’ evidence.
‘Good enough’ evidence
Sometimes we are asked, how do we know our evidence is good enough?
Our answer is, it depends on how you are going to use it. Good evidence is useful evidence, so you need to ask ‘good enough for what’. There is no absolute standard.
But it can help to ask yourself some questions and here we use a simple framework called TREBL. Based on work by Levitt et al each letter stands for a principle.
T is for Transparent, this means that you should be clear about the limitations of your evidence. Evaluation is almost never perfect, be clear about the gaps, identify the thin ice, don’t skate on it. for example you might say that your evidence is based on a sample, you have taken steps for it to be representative, but you cannot guarantee that it is,
R is for Relevant, this means your evidence sheds light on the question you are asking and is still up to date. A good example is using national statistics, when you can’t attribute the impact on them to your project. This might not then be relevant information.
E is for Enough! This is about striking a balance between having enough evidence to be convincing, but also being proportionate to the type of work you are doing. For example you wouldn’t ask someone to fill in a 10-page questionnaire for a 5-minute piece of support. You might have to accept that having a light touch method gives enough evidence.
B is for Believable, this means that the evidence is credible and plausible, Ie, accurate ( people were telling you the truth] it’s representative (it’s a fair sample], and reliable (you would get the same results if you collected the same information again)
L is for Legitimate, this means that the evidence is coming from the right sources, this might mean coming from the person that is affected, or if that’s not sufficient from a range of sources (for example small children might not be able to give you a lot of feedback, but evidence can be supplemented with family member or professional observations ) it’s also about having a good balance between qualitative and quantitative information, (stats and stories).
By using the TREBL framework you can establish how good your evidence is. Paradoxically, being honest about limitations strengthens your evidence and enables both you and others to make better decisions based on that evidence