Friday, December 19, 2008

Top 5 Intelligence Analysis Methods: Analysis Of Competing Hypotheses (#1)

(Note: I apologize for how long it has taken me to get here. Conferences, classes and life in general conspired to get in the way this week. For the patient, here is the last in this series of posts...)

Part 1: Introduction
Part 2: What Makes A Good Method?
Part 3: Bayesian Analysis (#5)
Part 4: Intelligence Preparation Of The Battlefield/Environment (#4)
Part 5: Social Network Analysis (#3)
Part 6: Multi-Criteria Decision Making Matrices/Multi-Criteria Intelligence Matrices (#2)

Analysis Of Competing Hypotheses (ACH) is probably the best-known intelligence analysis method today. Invented by Richards Heuer over 30 years ago and made famous in his intelligence classic, the Psychology of Intelligence Analysis, ACH is widely taught and conceptually easy even for entry-level analysts.

In addition, it was specifically designed to work in all kinds of situations with any kind and quality of data. What is less clear is that the method produces unequivocally better estimative results. While the method is rooted fundamentally in the scientific method, studies testing the value of the method as a way to improve forecasting have been few and the results have been mixed (In no study have the results been worse than without the method but some studies have shown that the method only helps certain subsets of analysts. For a good list of these studies see the Notes List at the end of the ACH article on Wikipedia).

I am not sure why this is so. My own impression is that a well done ACH provides a better estimate in less time and with more nuance than virtually any other method available.

We teach ACH here in our freshman classes. I see many, many students struggle not with the basic concepts of ACH but with the details. I see countless examples each year of student projects where they have improperly executed the method (in much the same way a student gets their first attempts at a calculus or chemistry problem incorrect).

In most cases, it is fairly easy to correct the mistakes and the students rarely have a problem seeing what they did wrong or in making the appropriate adjustments. It is less clear to me that, at this early stage in their education, they are able to transfer this knowledge from one type of problem to another, however. We try to reinforce all our methods in upper level classes but the opportunities for reinforcement in the real world are slim (we rarely find, for example, that students are required to use structured methods in their internships).

My own instincts tell me that ACH (and many of the experiments involving it -- including our own) is a powerful method but won't get a fair test until such a test is done with analysts who have worked with the method on multiple problems and in multiple circumstances. To be honest, I suspect that this is true with all of the methods I have discussed in this series. Deliberate practice seems to be a key component of expertise in multiple other fields and I imagine this is true when it comes to intelligence analysis methods as well.

Improving the quality of the final estimate is only one (albeit an important) way that a method should contribute to a quality intelligence product, however. ACH brings much more to the table in my estimation and it does this immediately, in even the earliest projects.

ACH can help the analyst at every stage of the problem, including modelling, collection and collection planning, and preparing a document for dissemination. It is a wholly transparent method and can very easily be used collaboratively. Its transparency is also crucial in helping instructors or managers identify problems in the analysis of the data. The transparency is also of enormous benefit in understanding and improving the analytic process after the fact as well. It integrates extremely well with various data resources and is very suitable for automation. We find that it is actually faster to use, particularly in a group setting, than most other methods (including intuitive analysis).

The way ahead is a little different here than with the other methods. We think we have a pretty good handle on how to teach ACH. The key, in my estimation, is to create opportunties to reinforce that teaching in and outside the confines of the classroom.


Anonymous said...

This was a great series of posts, Kris. I pointed to it yesterday. I've often wanted to find a quick reference on different analytic methods and now I've got one!

Kristan J. Wheaton said...


Thanks! I have heard the same thing from quite a few people. I was surprised at how well received this effort was.


Allen Thomson said...

ACH looks, to my non-expert eye, a lot like Pierce's "abductive reasoning." (

Is there an actual connection, or am I just imagining things?