Christian Gade
This blog post is based on the Evidence & Policy article, ‘When is it justified to claim that a practice or policy is evidence-based? Reflections on evidence and preferences’.
When you search the internet, you will find a myriad of claims about different practices or policies being evidence-based. To avoid ‘evidence-based’ becoming merely a buzzword that everyone can throw around and use whenever they deem it suitable, it is important to consider the conditions for when it is justified for you as an individual or organisation to claim that your practice or policy is evidence-based.
My argument is that this is the case if, and only if, three conditions are met – an argument that suggests that it depends on subjective preferences whether you are justified in claiming that your practice or policy is evidence-based, and that it is important to give more attention to the normative dimension of the field of evidence-based practice and policy.
The first of the three conditions presented in my argument is that you have comparative evidence about your practice’s or policy’s effects compared to the effects of at least one alternative practice or policy (which could also be a placebo practice). Claiming that your practice or policy is evidence-based is to claim that it, rather than some alternative, is supported by evidence, and you can only be justified in claiming that if you have comparative evidence.
The second condition is that your practice or policy is supported by the comparative evidence according to at least one of your preferences in the given practice or policy area. If the evidence, based on your preferences in the given area, does not support your practice or policy in any way, then you are not justified in claiming that it is evidence-based. It is not enough that the evidence supports your practice or policy according to some potential preference one might have. If that were the case, then one would – as the list of potential preferences is endless (and given that the other conditions were met) – be justified in claiming that any practice or policy is ‘evidence-based’, which would render the term meaningless.
Finally, the third condition is that you can provide a sound account for the above-mentioned support by explaining the evidence and preferences that lay the foundation for your claim. If you can’t explain this (not even with the support of others) but simply state that your practice or policy is evidence-based ‘because you say so’ or something similar, then your claim is not justified.
It should be noted that my three conditions do not exclude any types of comparative evidence, nor any preferences. Some might argue that only some types of evidence, and that only preferences that are somehow ‘objectively’ valid or legitimate, should count in the field of evidence-based practice and policy. However, the problem with such an approach is that different epistemic and moral communities will probably never agree on what the appropriate evidence and preferences are.
Thus, instead of excluding any types of evidence and preferences, I suggest a transparency approach where the important thing is transparency about both evidence and preferences. Based on such transparency, I may state that it does not matter to me whether you are justified in claiming that a specific practice or policy is evidence-based, either because I do not trust the kind of comparative evidence you have, or because I do not share the preferences that underpin your claim.
My argument suggests that preferences, which are part of the normative dimension of the field of evidence-based practice and policy, ought to receive more attention within this field. Practically, when doing research in the field, the collection of evidence should be guided by the practitioners’ (policymakers’, etc.) preferences, including how much relative weight they ascribe to different preferences. Thus, researchers should be more interested in exploring practitioners’ preferences as a first step in their research.
My article has received valuable commentaries by S. Joshua Thomas and Zachary P. Neal. Based on my distinction between evidence and preferences, Thomas provides appreciated elaborations on how the normative dimension of the field of evidence-based practice and policy is not limited to preferences, as evidence itself may be value-laden. I completely agree with Thomas’ reflections.
Neal relates my argument to the epistemologies of Roderick M. Chrisholm, Keith Lehrer, and Alvin I. Goldman and writes that just as their epistemologies have been criticised, he suspects that there are valid critiques of my argument. To offer an example, he refers to my third condition and writes that practitioners should not be required to be able to explain the nuances of the evidence that underpins their claim about their practice or policy being evidence-based, as this is the role of brokers, etc.
I agree with Neal on this point. However, I personally have a broader interpretation of the third condition where the practitioners may, in fact, rely on brokers, etc., to help provide an account of the evidence. Similarly, practitioners may also rely on others to assist in providing an account for their preferences.
Image credit: Image created with the assistance of DALL·E 3.
Christian Gade, PhD, serves as an Associate Professor at the School of Culture and Society at Aarhus University. Additionally, he holds the position of Director at the Aarhus Centre for Conflict Management (Aarcon) and coordinates the Master’s degree program in Human Security at Aarhus University. Presently, he acts as a co-principal investigator of the Konfliktråd Impact Project, a Danish randomised controlled trial comparing the effects of mediation and restorative justice conferences.
Read the original research in Evidence & Policy:
Gade, C. (2023). When is it justified to claim that a practice or policy is evidence-based? Reflections on evidence and preferences. Evidence & Policy, DOI: https://doi.org/10.1332/174426421X16905606522863. OPEN ACCESS
Neal, Z.P. (2023). The epistemology of evidence-based policies and practices: a comment on ‘When is it justified to claim that a practice or policy is evidence-based? Reflections on evidence and preferences’ by Christian Gade. Evidence & Policy, DOI: 10.1332/17442648Y2023D000000011.
Thomas, S.J. (2023). On the value-ladenness of evidence: a comment on ‘When is it justified to claim that a practice or policy is evidence-based? Reflections on evidence and preferences’ by Christian Gade. Evidence & Policy, DOI: 10.1332/174426421X16905606522863.
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Breaking the glass in the ‘Overton Window’: the role of adversarial co-production
Breaking the Overton Window: on the need for adversarial co-production
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