Charles
Ungerleider, Professor Emeritus of Education, The University of British
Columbia
[permission
granted to reproduce if authorship acknowledged]
Like many, my attention has been drawn to the impeachment hearings in
the United States. Barely a few seconds after a bit of testimony, someone cherry-picks
some testimonial snippet to tweet accompanied by emotive language. Both the
snippet and the emotive language are offered as proof of the twitter user’s
previously held position.
The Oxford dictionary defined post-truth as “relating to or
denoting circumstances in which objective facts are less influential in shaping
public opinion than appeals to emotion and personal belief.” The dictionary
lists as an example of usage: “in this era of post-truth politics, it's easy to
cherry-pick data and come to whatever conclusion you desire.” In other words,
concern for the truth is no longer a consideration.
Educators should
be especially vigilant about promoting the quest for truth and the evidence
upon which truth depends both for the students for whom they are responsible
and for themselves. It is though the cultivation of
respect for evidence as reasonable grounds for belief and action that educators
safeguard society from tyranny. Educators who do not respect evidence
with regard to their own practice are poor models for students. They are unlikely
to encourage students to respect evidence or to use it.
Without
splitting hairs too finely, there are probably three notions of post-truth
that, in practice, get conflated. At its
worst, post-truth means “I don’t need evidence to come to a conclusion” – a
complete rejection of evidence even when evidence is available. Another version is: “I distrust and reject the
evidence that you use. I don’t deny that there may be evidence, I just deny the
evidence you cite in support of your claims. I will assert my claims even in
the face of the evidence you present.” And third version of post-truth is “I
prefer my evidence to the evidence that you cite in support of your claim and
will draw my conclusions on the basis of the evidence I prefer.” This is what
some have called alternative truth.
What is evidence?
Evidence is
the available body of facts or information indicating whether a belief or
proposition is true or valid. We use evidence to show the claims we make are
reasonable or that our actions are right. If someone is committed to seeking
the truth, they cannot cherry-pick the data that will support their preferred
conclusion(s) or justify the course of action they wish or have pursued.
Those
committed to seeking the truth will suspend judgement until a claim is supported
by the evidence. In the post-truth world, conclusions are often made before
evidence supporting the claim is ‘discovered’ and contrary evidence debunked.
Evidence requires
objective evaluation, meaning that the evidence that something is true should
be independent of my individual proclivities, emotions, and interpretations or
of yours. The evidence I cite in support
of my claims should be subject to independent verification. The evidence should
have been gathered using methods sufficiently well-described and well-accepted
that others can apply them to arrive at an independent appraisal of the claim.
Those
committed to truth seek the facts that would challenge the claim they wish to
make in order to ensure that claim will withstand close examination and
challenge. Experts seek rigorous review by their peers in order to ensure that
their work withstands close scrutiny.
People –
especially people who claim expert (professional) status - should not do
something that is contrary to the available body of evidence without strong
justification. Contrary to common usage, professional judgment does not refer
to the judgement of the individual practitioner. It refers to the collective
judgment of professionals who are competent to examine dispassionately the
entire body of evidence that has been accumulated. Such examination takes into
account many things, among them: how the topic or issue was defined, how the
evidence relevant to the topic was gathered, how it was analyzed, and whether
the conclusions drawn are supported by the evidence collected. In assessing the
entire body of evidence available on the topic, educators should seek to
determine if there is rational convergence of opinion among those qualified to
appraise the evidence, taking into account its quality and its strength.
Simply
citing research related to one’s beliefs or actions is a common form of cherry
picking evidence to support one’s inclinations or behaviour. It is not unusual
to read or hear a ministry, school board or school proclaim that an initiative
or policy is evidence-based because someone has found a few studies that seem
broadly related. Those making strong claims about what one should do or what
one should believe should be able to show the specific link between the
evidence the initiative or policy.
The Fraser
Institute is a good example of an organization that uses evidence selectively.
It cherry-picks data and presents it in a manner that will support the
conclusion it seeks. To destabilize support for public services in general, and
public education in particular, the Fraser Institute is selective about the evidence
that it uses and the manner in which it presents the evidence to give the
impression that public education is not doing very well. The “studies” produced
by the Fraser Institute lack objectivity because its views about what is the
case is guided by ideology rather than evidence.
How much evidence is
sufficient?
Readers will
no doubt notice that I’ve referred to reviewing the entire body of evidence.
There are a number of practical reasons for this recommendation. Much educational
research has been carried out by individuals who have a personal stake in the
outcome of the study. Most investigators do not consciously attempt to
influence the outcomes of a study, but nonetheless may inadvertently influence
the results through the decisions they make about the research methods they use
or the inferences they draw. This threat to objectivity warrants looking beyond
single studies to the larger body of work.
It is
regrettable that there are few, if any, follow-up educational studies that
replicate an initial study to determine, for example, whether the same result
was found under the same conditions or whether the result of the initial study
applies to contexts or to students who differed from those in the original
study. In the absence of such replications, looking across the body of work provides
valuable, though imperfect, evidence about such matters.
We are
fortunate that it has become increasingly common to conduct systematic reviews
of evidence or meta-analyses of evidence. Many such reviews are available to
educators from the What WorksClearinghouse, the CampbellCollaboration, Eurydice web
sites, from publications such as the Review of Educational Research or
Hattie’s visible learning series, and from systematic reviews published in
individual journals. Systematic reviews
are not flawless, but they provide a firmer foundation for claims about policy
and practice than single studies or groups of studies selectively chosen to
suit the policy or practice one wants to pursue.
Why evidence matters.
Tyranny
becomes more likely in a post-truth environment where prominent persons and
institutions manifest a blatant disregard for the truth, little respect for
evidence, and antagonism toward dissent. One of the purposes of public schooling is to
cultivate the ethical commitment to truth and respect for evidence. And the
responsibility of doing so falls upon educators.