Summary:
In his
2018 article in the Journal of Intelligence and National Security, Mr.
Nicholaos Jones, a Professor of Philosophy at the University of Alabama at
Huntsville, gives an epistemological critique of Analysis of Competing
Hypotheses (ACH).
Mr. Jones
begins by laying out his process for evaluating hypothesis testing
methodologies. He first asserts that a methodology is “good” or “better” based
on how it meets the reasoning goals of the analytical process. He identifies
two initial reasoning goals: reliability and discrimination. Jones defines
reliability in terms of how some body of evidence regards one hypothesis is
more likely than a second hypothesis; a hypothesis that is more truthful than
its alternative(s) will rank higher. In this case, discrimination means being
able to partition hypotheses into ranks. Jones states that the reasoning
criteria/goal of discrimination is easier to meet than reliability. He also
states that discrimination is necessary, but not necessary to be approximate,
to meet the criteria of reliability.
Before
identifying alternative/competing methodologies to ACH, in this case Falsificationism
(strict falsification), Bayesianism, Explanationism (inference of best
explanation), Jones identifies additional reasoning goals of tractability and
objectivity. Jones states that a methodology has tractability if it is
efficient and elegant (i.e. simple) to use. Objectivity means the ability to
minimize the effects of cognitive bias on reasoning by reducing the reliance on
“subject evidence.” In assessing alternative methodologies, Jones states, in
his assessment, that determining reliability of a method is difficult and
avoids it. Each of the three identified alternatives have two strong and one weak
reasoning goals.
Jones
believes that ACH does about as well as alternative methodologies in terms of
three reasoning goals that he stated were easier to assess. Jones believe the core
of ACH is the third through fifth steps of ACH as laid out by Heuer. Jones
interprets these steps through either strict or colloquial interpretations of
Heuer’s third step on evidence consistency with regards to the hypothesis. Strict
interpretation requires the absence of any logical contradictions in evidence
whereas the colloquial interpretation requires evidence be “at least weakly or
moderately plausible.” Under both interpretations Jones, regards ACH as
stronger than alternative methodologies.
Jones then
decides to complicate his ongoing analysis with a final reasoning goal:
stability. In order to define stability, Jones breaks down hypothesis testing
into three steps: 1) Inputs; 2) Operation; and 3) Rankings. Stability in this
case means that every execution of a hypothesis testing (methodology) operation,
using the same evidence or inputs, will yield the same result. Jones suggests
that once stability is added, ACH becomes unstable. He lists three scenarios to
highlight his critique: “first, when multiple competing hypotheses are
consistent with all available evidence; second, when exactly one hypothesis is
consistent with all available evidence; third, when none of the competing
hypotheses are consistent with all available evidence.” The first case
represents a problem of abundant fit, which Jones believes can be remedied with
more evidence which changes the nature of the problem into the second or third
case. Meanwhile the second case represents a problem of redundancy because if
all evidence fits a single hypothesis, then revising competing theses, deleting
or simplifying evidence, and further refining the process will yield an
identical result thus adding complexity to the methodology, making it less tractable.
The third
case highlights Jones case that ACH is unstable under both strict and
colloquial interpretations of evidence consistency, albeit for different
reasons. In a strict interpretation of the third case, ACH gives no way of
determining which of the inconsistent hypotheses is more likely. In a
colloquial interpretation, Jones argues that in cases where a generalized piece
of evidence is separated into its constituent pieces of evidence, arbitrary
factors influence the outcome. So, in a case where the likely hypothesis
doesn’t chance, the individualization of evidence can affect which of the other
two hypotheses is more or less likely, making ACH unstable.
Jones the
suggests that by favoring generality of evidence or increasing nuance or
subtlety of evidence diagnosticity, the stability critique can be avoided.
Jones argues that the generality rule fails because 1) it is too strong; 2) the
rule is ad hoc and presents bias; and 3) the rule is unnecessary. Jones then
argues that considering the diagnosticity of the evidence, as suggested by Heuer,
may provide the solution to the generality problem. Jones concludes that
weighting diagnosticity of evidence further complicates ACH because of the way
to select for individualized evidence is arbitrary and therefore does not lead
to stability.
Jones
believes that ACH is superior to other discriminatory methodologies by using a
procedure to “aggregate consistency judgements.” While it is superior in this
regard, ACH’s shortcoming is in the necessity to summarize evidence over
specific individual items within the evidence. Jones sees this a structural
flaw in ACH. In his view, there is no adequate solution to what he terms as the
Generality Problem. Jones ultimately suggests that the methodology of ACH does
not matter as much as the way the analyst uses the method and the analysts “luck
or intuition.” While an analyst can yield effective results from ACH, Jones’
key criticism is in the lack of universal tactics for ranking/individuating
between analysts’ evidence. He suggests that further research on ACH focus on
techniques for individuating evidence, which will enhance transparency of the
ACH operation and eliminating arbitrary or subjective bias into their analytic
products.
Criticsim:
My primary
disagreement with Jones’ approach to ACH is that he only tackles the
methodology from the approach of a pure academic, as opposed to that of a practitioner. As an analyst, we are taught that there are logical shortcomings from the get go. The application of ACH to an analytic problem is intended to be a guide
when examining your hypotheses and evidence. Jones’ critique that the process
is redundant is correct but, in my opinion, I believe he misses the primary
purpose of ACH. The methodology provides a structured approach to evaluating
evidence that may be self-evident but also allows the analyst to ask essential
questions of the process: are the hypotheses too broad/narrow? Is there more
evidence to be found? Is the evidence redundant? Etc… In Chapter 8 of The Psychology of Intelligence Analysis,
Heuer starts by stating,
“Analysis
of competing hypotheses…is a tool to aid judgment on important issues requiring
careful weighing of alternative explanations or conclusions. It helps an
analyst overcome, or at least minimize, some of the cognitive limitations that
make prescient intelligence analysis so difficult to achieve… Because of its thoroughness, it is
particularly appropriate for controversial issues when analysts want to leave
an audit trail to show what they considered and how they arrived at their
judgment.”
In the excerpt
shown above, Heuer clearly writes that ACH is a tool for the analyst to
question his process and show their steps in their work. Again, by purely
approaching ACH from an academic or logical standpoint, I believe Jones overplays ACH’s
pitfalls which are clearly highlighted upfront by Heuer.
Going back
to the redundancy issues that Jones highlights, I believe that, again, Jones’
misses the point. The grand simplicity of ACH is that the process is easily
repeated to show all possible alternatives. While that adds, in Jones’ view, complexity,
it is as Heuer states, the auditing process for the analyst to show how he came
to his final analytic conclusion.
Overall, I
agree with Jones’ conclusion that a procedure or technique for objectively
individualizing evidence would enhance ACH’s reliability and improve analytic products.
Link: https://www.tandfonline.com/doi/abs/10.1080/02684527.2017.1395948
Based off your summary and critique I would agree that not approaching the evaluation of ACH from a practitioner perspective is a major flaw of his assessment. Did Jones address this as a shortcoming in his research?
ReplyDeleteNo. Jones chose to purely examine ACH from a epistemological perspective (which is by looking at the logic and functionality of ACH's basic method and steps). I believe that critique has some valid points, which I highlighted, but he does not seem to reflect on Heuer's intentions for ACH. Heuer did not intend to create a "one-stop shop" for testing analytic theories. He chose it as a simple and, what Jones point out as a structural flaw, repeatable method.
DeleteHi Harry, interesting critique on Jones' arguments regarding the effectiveness of the ACH methodology. In reading several of these blog posts on ACH, it appears that a common issue that arises is the lack of a standard way to weight individual evidence. Jones in particular, seems to suggest that evidence diagnosticity can resolve the issue of stability. At the same time, however, Jones also states that as long as the diagnosticity is arbitrary it does not resolve the stability issue. Does Jones mention or consider any alternative means of weighing evidence, whether through assigning numerical values for strength of consistency, ranking of evidence, or otherwise? Or does Jones simply write-off weighing evidence as an arbitrary task without considering possible alternative measures?
ReplyDeleteTom,
ReplyDeleteJones does not suggest other methods for weighing evidence. As is the title, this is purely a critique. Jones does not suggest other methods for weighing or assessing the diagnosticity of the evidence to add the efficacy of the method.