I don’t think many of us would associate the scientific method with a leak in a basement.  In this case, however, a big leak, a mini-flood, in the electrical and modem rooms of a commercial building – not the place you want rogue water.

In chasing down the cause – three possible causes ended up on the table at different times, with the third still there – it struck me I was following the scientific method without thinking.  Nice that it came naturally – it should after a few years investigating failures.

This is how I used the scientific method in this case:

1. I thought – hypothesized – about the cause of the leak based on the evidence I initially had (see below),
2. fixed that cause, so I thought,
3. checked if the rooms were still leaking – a test of a hypothesis in the scientific method -,
4. saw that they were
5. so, modified my thoughts on cause – modified the initial hypothesis like in the scientific method,
6. fixed the modified cause,
7. checked if …,
8. etc. etc…

It’s not unlike differential diagnosis in medicine. (Ref. 1) Time consuming and expensive at times but thorough and reliable – the way it must be in engineering investigation and medicine.

***

I was retained by the owners of a medium sized three story, commercial building to determine the cause of a leak in the electrical and modem rooms.  The rooms served several businesses in the building.  The rooms were separated by a partition and located on the right side of the finished basement next to the concrete walls.

I started my engineering investigation doing standard tasks.

Staff briefed me on the leak problem.  They told me that water appeared on the floor of the rooms during heavy rain and strong winds from the front, right corner of the building, the southeast.  The water flowed across the floor until the storm blew through and the rain stopped.  The source of the water behind the finished walls could not be seen.

The leaking had been going on for several years since building renovations that included electrical services.

I examined the interior layout of the building and also measured the location where the rain water first appeared on the floor.  I referenced the measurements to the rear and right, exterior walls.

I then examined the exterior layout of the building and measured the location of all features on the roof, and also on the right, brick-clad wall where the water was appearing in the two rooms.  The features on the roof and side included roof drains, exhaust pipes from wash rooms, air conditioning units on the roof and an electrical service mast on the right wall.  All places where rain water might get in.

I compared the interior and exterior measurements.  This revealed that the service mast was in the same location on the outside of the building as the mini-flood on the inside.  Good evidence

Electrical service mast construction

The service mast was a 4″ diameter PVC pipe that extended from the roof down to near the bottom of the brick wall and the top of the concrete basement wall.  The service mast carries electric wires/cables from the street to the building.  The mast/pipe was vertical to the bottom of the brick wall then horizontal through a 90 degree elbow into the wall.  The joint between the service mast and the brick wall was caulked.  Fairly standard construction.

The electrical cables from the street entered the service mast at the top through three 1.5″ x 2.5″ holes at the underside of a canopy.  The cables have what is called a “drip” loop so rain water on the cables can drip off before they go into the holes.

I hired a carpenter to take down part of the finished interior wall in the electrical room.  This revealed that the horizontal electrical service mast entered the rooms through a circular hole cut in the top of the concrete basement wall.  The mast then continued along the top of the partition between the electrical and modem rooms.

The hole in the concrete wall appeared to have been drilled several inches too low in 2004.  A plug of concrete was placed between the underside of the mast and the bottom of the misplaced hole to fill the gap.

Rogue water in the wrong place

Water stains on the bottom of the plug of concrete and down the concrete wall indicated the water on the floor was getting into the rooms at the joint/contact between the plug of new concrete and the old basement wall concrete.

Droplets of water and running water were seen at and below the plug of concrete during future rain and wind storms out of the southeast.  Very good evidence.

Based on the evidence I had at this point, January 22, 2020, I thought – my initial Hypothesis #1 – that the leak and the mini-flood was caused by rain water running down the outside of the service mast and into the electrical and modem rooms through inadequate caulking.

I hired the carpenter to apply additional caulking on top of the old and this was done.

Heavy rain and strong winds on February 27 and the floor mini-flooded again.  More evidence – the water is getting in somewhere else; the exterior caulking was not inadequate.

A suspicious gap and “drip” loopless cables

I noticed during the wind and rain storm in February that there was a gap along the steel heading to a window next to the electrical mast and that the steel was rusted.  Could rain soaked up-gusts of wind get into the window gap and mini-flood the floor?  Hypothesis #2.

But before testing Hypothesis #2 by caulking the gap along the window heading I decided to take the back off the elbow in the PVC electrical mast.  This was where the mast changed from a vertical mast to a horizontal mast and on into the electrical room.

I saw that the bottom of the interior of the mast was water stained and covered with dark, damp dust to an estimated 3/4″ up the circular interior of the mast.  The electrical cables were there with caulking everywhere around the cables filling the space between the cables and the inside of the horizontal mast.

Except for an estimated 1/2″ gap or hole at the top of one of the cables between it and the caulking.

The cables did not have a rain water “drip” loop like at the top of the service mast before going into the horizontal section of the mast.

The purpose of the caulking filling the interior of the mast around the cables was to intercept and shed any rain water that might get into the vertical mast and flow down the cables to the caulking.  The water would then flow across the caulking and onto the bottom of the service mast elbow to drain through small holes drilled there for the purpose.

However, this would not happen completely because of the 1/2″ gap at the top of one of the “drip” loopless cables – there’s no caulking at the gap/hole to intercept rain water.

The culprit? Rain soaked up-gusts of wind and “drip” loopless cables?

Some rain water was getting into the holes in the canopy at the top of the service mast.  This was evident by the water stained bottom and damp dust at the bottom of the mast elbow.  I can easily imagine rain soaked up-gusts of wind getting into the canopy holes.

Could enough water get in and some flow down the “drip” loopless cable and through the 1/2″ gap in the caulking at the top of the cable?  Then through tiny holes that might exist in the elbow at the bottom of the mast above the concrete basement wall?  From there into and through the plug of concrete and down the wall to mini-flood the floor below?  I thought so.  Hypothesis #3.

I plan to caulk the 1/2″ gap above the cable when the weather warms up.  The Duct Seal caulking used for this work is firm at room temperatures of 20 to 25 degrees, and difficult to work.  It must be easy to work to ensure adequate caulking of the gap in the tight 4″ diameter space inside the elbow at the bottom of the electrical service mast.

I’ll then wait for the next heavy rain and wind storm – hopefully soon; sorry – to test my third hypothesis.  I’ll let you know the results in an update of this blog.

Reference

1. Blog on Differential diagnosis in medicine and forensic investigation, and soft, initial thoughts on cause.  Posted December 20, 2019

Judges, unlike forensic experts, are too intuitive in their decision making and too little, deliberative and objective.

The facts, evidence and case law are considered in a dispute but then intuition kicks in – sometimes before the facts – and sneaky bias always lurks in the shadows.

To be fair, judges are human and often dealing with a full docket and a lot of issues.  They’ve got to work fast.  They perhaps can’t be expected to be completely objective like experts who investigate and opine on one issue – for example, the cause of a failure or accident in the built environment.

Advocates for the parties involved in a dispute are partial to their client’s interests, but that’s their job.

Considering the vested interests of the parties in a dispute, an expert must be objective and impartial.  If for no other reason but to serve as a touchstone for the judge when he or she drifts too far from deductive reasoning.

***

I concluded the above based on Ref. 1 and reading the legal references and studies in the Bibliography at least once, one paper twice and another three times.  How judges judge was the topic studied and reported on in this material.  However, I can imagine the findings apply a little to other arbitrators – human nature being what it is – like juries, the Arbitrators in ADR (alternate dispute resolution) and insurance claims managers and consultants.

***

I learned of this situation – too subjective, intuitive, biased judging – when I thought to include judging in an update of a recent blog on the similarities in engineering and medicine. (Ref. 2) I was prompted to do this on reading the judgement in a case for which I provided expert services.

I know now that I can’t do that.  There are few similarities between how judges judge and engineers engineer.

I got in touch with my client in the case (Ref. 3) and another in Toronto and asked for reference material on how judges judge.  I got the material in the Bibliography which is very good.

I read the material and was shocked to learn the extent to which intuition, bias, hunches, culture, etc. figure in a judge’s decision-making, in addition to objective deliberation.  Sometimes intuition figures almost exclusively.

It’s serious enough that people in law and related fields who study this situation must develop models and theories to try and understand and explain what goes on.  They’ve got to resort to the scientific method to get a handle on how judges judge.

Anything reflecting the scientific method, that is key to the expert’s work, was almost nowhere to be found in the decision-making. Too often the decision is intuited then evidence and case law sought to support it.

The cost of the judicial process seems to be part of the problem.  The dockets are often full and a decision takes time and costs money regardless of whether it’s intuitive, deductive or a mix.

However, regardless the cause, there does appear to be a real need for more deliberate decisions by judges if what I read is any indication.  Increased accuracy of decisions in dispute resolution – therefore justice and the fair settlement of claims – may be worth the cost of reform.  Justice depends on deliberation not intuition. 

In the meantime, experts must stay the course and be objective and impartial – as expected of us by the judicial process – and show the way forward for judges, and for arbitrators, in general.

References

1. Corbin, Ruth M., Chair, Corbin Partners, Inc. Toronto, Personal communication, March 30 and April 10, 2020
2. Differential diagnosis in medicine and forensic investigation, and soft, initial thoughts on cause.  Posted December 20, 2019
3. Christofi, Andrew, NDD Law, Halifax, Personal communication, April 1, 2020

Bibliography

1. Capurso, Timonthy J. (1998) “How Judges Judge: Theories on Judicial Decision Making,” University of Baltimore Law Forum: Vol. 29: No. 1, Article 2.
2. How Judges Make Decisions, Canadian Superior Courts Association, Ottawa, Ontario 2018
3. Read, Lucy, Arbitral Decision-making: Art, Science or Sport?  The Kaplan Lecture 2012
4. Guthrie, Chris, Rachlinski, Jeffrey J. and Wistrich, Andrew J. Blinking on the Bench: How Judges Decide Cases. Heinonline 2007/2008
5. Rachinski, Jeffrey, Guthrie and Wistrih, Andrew.  Inside the Bankruptcy Judges Mind. Boston University Law Review, Vol. 86:1227 2006
6. Corbin, Ruth M., Several examples of reasons for decision illustrating assessment of evidence 2020
7. Carlson, Nancy, Judgement and Decision Making. Presented to Ruth M. Corbin, May 2, 2017. Judges Should Not be in the Business of Defying Expectations

For example, evidence like knowing a steel girder stands upright on blocks on the girder-factory floor or outside before it goes to the bridge construction site.  Not braced sideways, not even a little. (Ref. 1)  Nor pulled sideways at the factory by a sling and cable connected to a crane oscillating in wind so strong workers left the site for safety reasons.

***

The bridge on 102 road over Groat Road, Edmonton failed during construction when girders buckled early on the morning of March 15, 2015. (Ref. 2, also Sources below)

The bridge consists of seven, 40-tonne girders.  Each girder consists of two 7.5 metre long end sections and a 43 metre long middle section.  The end sections are 4.5 metres deep arching up to 3.0 metres at the middle section.  The sizes are approximate.

Six of the seven girders were in place at the time of the failure.  Three of the six girders failed when the 43 metre long middle sections buckled sideways.

The girders are lifted into place by a crane with a cable and a sling attached to the top (flange) of the girder.  The sling was still attached to the outside girder, the last one placed that day, when the workers went home.

I analysed the reason the girders buckled to demonstrate how experts form and modify hypotheses on cause during a forensic engineering investigation. (Ref. 3)

News reports state that the preliminary cause of failure was inadequate cross-bracing.  I don’t agree.  As well, some time ago, I concluded after my second modified hypothesis that the failure was due to a construction crane tugging on the top of the outside girder together with inadequate cross-bracing. (Ref. 3)  I no longer agree with that combo conclusion either.

A third modified hypothesis is needed.

The tiny bit of evidence for this? If steel girders can rest on the ground in the girder-factory yard with no cross-bracing, and not bend sideways in the middle or topple over, why not overnight on the bridge?

Do you want more evidence? The ends of the middle girders that buckled were also bolted to the braced end girders.  This added to their inherent stability that kept them upright on the girder-factory floor or on the ground outside.

So what happened in Edmonton in March, 2015?

There may have been contractual requirements to put cross-bracing in place but the lack of adequate bracing was not the cause of the girders buckling.  The girders buckled because the crane boom oscillated in the wind overnight causing the crane cable and sling to tug on the top of the outside girder until it bent sideways.  There was no other reason. The two inner girders bent because they were attached to the outer girder by a bit of cross-bracing.

***

Like I said, the wind was so strong that night that the construction site was shut down for safety reasons.  Crane operators lower their crane booms in strong winds. (Ref. Sources)  Why wasn’t the boom lowered that night?

The 1.0 metre buckle sideways was well in excess of the 0.3 metre buckle that would occur under service or construction loads. (Ref. Sources) The magnitude of the buckling indicated that the force from the crane tugging on the top of the girder was greater than the construction load, perhaps much greater.  Why wasn’t this tugging load included in the construction load by the bridge designer?

***

If all bracing was in place I would still put money on all the girders bending at least a little, say, a few millimetres to centimetres, as the crane tugged on the top of the girder.  Some pictures may show that the adequately braced end girders where they were connected to the middle girders bent sideways a little too.

***

Life was good for the quite stable, free-standing girders at the girder-factory.  Then they were taken to the bridge construction site and hooked up to the oscillating crane boom and tugged sideways.  They didn’t stand a chance after that.  The Edmonton bridge was destined to fail for that reason alone – a failure waiting to happen.

References

1. Jamie Yates, P.Eng., Civil Engineer, J. B. Yates Engineering Ltd, Fall River, Nova Scotia, Canada. Personal communication, March 9, 2020
2. Google: Edmonton bridge failure, Groat Road, Buckling, etc. to see photographs of the buckled girders.
3. Bridge failure in litigation due to inadequate bracing – City of Edmonton.  But, inadequate for what?  Posted March 15, 2016

Sources

I studied various photographs on-line including construction photographs taken at the time of the failure.

I spoke with Barry Bellcourt, the Road Design and Construction Manager for the City of Edmonton in 2015, also Bryon Nicholson, Manager of Special Projects. Barry mentioned the litigation and the city’s position.

I also learned from him that the bridge consists of seven, 40-tonne girders.  Each girder consists of two 7.5 metre long end sections and a 43 metre middle section.  The end sections are 4.5 metres deep arching up to 3.0 metres at the middle section.  The sizes are approximate.

I saw and photographed the underside of the repaired bridge girders from Groat Road in early August, 2015 when I was in Edmonton.

I understand it was windy the night the girders buckled and that was the reason workers were not on the job.

I spoke with four companies in Nova Scotia that operate cranes.  I learned that crawler crane booms move in the wind; flex and sway.  There is greater movement sideways because there is less strength that way.  Telescopic booms move more than lattice booms because of the greater surface area.  Booms are lowered to the ground in strong winds.  One company doesn’t operate its cranes in winds of 50 km/hr or more.

I also talked with Amjad Memon, P.Eng. a structural engineer with the Nova Scotia Department of Transportation, about the Canadian Highway Bridge Design Code.

Would you prefer a house constructed on ground that’s subsiding or one on ground where sinkholes pop at the surface?  A “mining house” (Ref. 1) or a “sinkhole house” (Refs 2, 3).  And if you had the one or the other, what could be done about it?

I thought this on reading the item in The Chronicle Herald on February 14, 2020 about Pictou County’s “mining houses”.  How an area’s coal mining history can sometimes come to the surface in unwanted ways and how these zones are not always known to home owners and buyers. (Ref. 1)

I would pick a “mining house” on ground underlain by deep mines rather than a “sinkhole house” underlain by Karst terrain – ground prone to sinkhole formation.  That’s because geo-engineers can analyse subsiding ground with some certainty and predict where it will occur and the amount.  It’s not so easy and cost effective to analyse and predict where sinkholes will occur. (Refs 2, 3)

(Geo-engineers – short for geotechnical engineers, a specialty of civil engineering)

Geo-engineers have lots of existing evidence on subsiding ground that they can analyse.  Evidence like the following:

• The location and depth of the underground mine,
• When it was worked,
• The type of ground overlying the mine,
• The contour of the ground now,
• The condition of the houses and,
• Published data on problems like this elsewhere in the world – like in the UK.

This is the evidence that I would gather together and analyse, and tell you a lot after I was done.

There’s also lots of information on this type of problem in the UK where I practiced for three years.

***

How does a “mining house” problem relate to forensic engineering?

It’s because the problem isn’t too much different from other problems in engineering, including forensic engineering.  You can learn a lot from existing evidence, sometimes very little existing evidence.

I was told about cracks in a building wall one time and the material used to construct the wall – the building was not in mining or sinkhole country.  The cracks had been caulked suggesting they were large enough.  I was not told about the shape of the cracks nor did I see the wall.  But, based on their size and a few years forensic and geo-engineering experience I knew the likely shape of the cracks and the cause.

***

It’s the same in mining country.  An experienced geo-engineer would examine the condition of the houses on the subsiding ground and beyond, input this to the other evidence and tell you a lot about the situation in the area.  Including where not to build or buy.  That’s possible in Pictou County.

References

1. The Chronicle Herald, page A8, Halifax, February 14, 2020
2. Update: Sinkhole news highlights a problem that can be fixed.  Posted April  8, 2019
3. Sinkholes: A litigious matter?  Posted September 15, 2017

Forensic investigation must be as thorough and objective as scientific research.  Peer review in science ensures that the research is well done.

Unfortunately, peer review in forensic work is not carried out very often.  And when it is there is a risk of bias in how it’s done.  This in spite of strict civil procedure rules governing experts and their reports.

***

Peer review in science is a process of evaluating scientific work, by an expert or a group of experts in the related field.  The scientific worker may or may not know the reviewer(s) – a blind peer review.  Similarly, the reviewer may or may not know the worker. (after Ref. 1 and Dr. Google)

Bias, or unreasoned judgement, can be blatant, or it can be unintended, sneaking up on us out of the ether. (Refs 2, 3 and 4)

Getting rid of bias in peer review is essential to forensic investigation.

***

The penny dropped for me on a better way compared to current practice when I got an e-mail from a reader, Ruth Corbin, after she read a blog I posted on peer review.  (Refs 5, 6)  A quick reply to Dr. Corbin included my initial thoughts on how I think we can get rid of bias.  These are bulleted below including some additional thoughts.

At present, experts investigate the cause of a problem.  They write a report on their investigation and findings.  The expert’s report goes to their client, the insurance claims adjuster or the civil litigation lawyer, and from there to the court or dispute resolution tribunal.  The investigation and report are seldom peer reviewed.  Except in a sense when they are rebutted by the expert for an opposing party.

Just how unbiased is the rebuttal report?  If phraseology in some reports is any indication, not much.

(You’ve all seen this phraseology, I’m sure.  Just to be really sure though, I’ll update this blog in future with some examples)

A peer review doesn’t have to be a crude denunciation or vetting of an expert’s work.  We can get rid of blatant bias.  We’re all here to serve the judicial and dispute resolution processes.  Finding errors and omissions and fixing them serves that purpose.

A peer or rebuttal review a little closer to that in science would help, one that involves the expert as little as possible in the organizing of a peer review of his work.  I think peer review procedures like the following will help, in decreasing order of preference:

• The court or tribunal retains the peer reviewer independent of the expert or his client.  This in the spirit of peer review in the scientific community.
• All the experts engage in “hot-tubbing” session, give their evidence concurrently and agree a joint report. (Refs 2, 7)
• The lawyer or adjuster retains a peer expert to review his work.  Because s/he wants a thorough and objective explanation of issues unfamiliar to the court or tribunal.  But third in preference because the lawyer or claims manager do have their interests.
• The expert retains a peer reviewer.  Because she would like to think they have done thorough work and reasoned well, particularly in the more empirical applied sciences like some medical and engineering specialties.  But fourth in preference because perception is everything in some fields of study.  An expert hiring someone to check his work might not look good.
• The rebuttal expert peer reviews the expert’s work.  I include this procedure because it’s a procedure that is sometimes followed.  It can work if the rebuttal expert pushes back against bias.
• No peer review at all of any kind.  The procedure assumes the expert’s work is thorough and objective and unbiased.

I believe the risk of bias is low when the court or dispute resolution tribunal arranges the peer review and high when the rebuttal expert does this.

Summary

We can get rid of almost all bias in peer review of forensic investigation and expert services.  There are several methods for doing this.  The one we chose will reflect our commitment to change and what we’re prepared to accept.  We’re accepting a lot of potential bias now.

References

1. Merriam-Webster dictionary
2. Biased experts cured with a soak in the “hot tub”.  A blog posted January 31, 2017 at www.ericjorden.com/blog
3. Expert witness forum looks at bias and other touchy subjects in forensic work. Posted March 8, 2018
4. Are experts being broadsided by bias unbeknownst to them?  Posted April 12, 2018
5. A Bundle of Blogs: On the need for peer review in forensic engineering and expert services.  Posted November 29, 2019
6. Corbin, M.Sc., Ph.D., LL.D., Ruth M., Chair, Corbin Partners Inc, and Mediator, Corbin Estates Law, Toronto
7. “Hot-tubbing” experts reduce the cost of civil litigation and ensure objectively.  Posted March 31, 2018

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada. ejorden@eastlink.ca)   

The phrase “differential diagnosis” caught my eye recently in light of some tendency in forensic engineering for the injured party to take the expert’s initial thought on cause as gospel and run with it.

Yet the forensic expert’s initial thought – an initial hypothesis – is based on just a little evidence and likely, quite subjective evidence.  For example, a briefing by the client, a  read of some documents and perhaps a walk-over survey of the accident or failure site.

Sometimes that thought/hypothesis is subject to revision like happens in the scientific method – and an embarrassment to all concerned if counsel decides to take the case or the claims manager agrees a settlement.

(Scientific method: A method or procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses. Ref. 1)

Differential diagnosis is a medical process.  It occurred to me that forensic experts could learn from medical doctors.

Differential diagnosis is the development of a list of possible medical conditions that might explain a patient’s symptoms.  The list goes from the most likely and urgent at the top to the least at the bottom.  The process involves several phases like forensic investigation involves several stages.  The early phases/stages are subjective in nature.  The process is well developed in medicine as explained by a friend and also Dr. Google. (Refs 1 and 2)

The phases of a differential diagnosis and their similarity to a forensic investigation are a little like the following:

Phase #1 Take history

In medicine, take a history from the patient about what she’s experiencing.  Interrogate and ask questions like a detective.  Try to figure out what’s going on.

In forensic work, take a briefing from the injured party or their counsel or claims manager about their slip and fall accident or the damage to their building.  Ask lots of questions.  Read existing documentation.  Consider different categories of accidents or failures.

Phase #2 Physical examination

Look, feel and listen.  Take the patient’s pulse and measure his blood pressure.  Examine him orally.  Listen to his chest (with a stethoscope).  Do a percussive examination (tap body with fingers and note the sound)

Walk over the site and visually examine the accident or failure scene and the structures there.  Measure and determine the condition of the structure before and after the failure.  Photograph and measure features characterizing the scene.  Take aerial video of the scene from a drone.  Excavate test pits and note the subsurface conditions.  Carry out initial skid resistance tests of the floor at a slip and fall accident. 

Phase #3 Additional investigative tests

Carry out additional tests like blood work, X-rays, MRIs and stress tests.

Take samples and do laboratory tests of the physical properties of materials that failed.  Do field tests and sample and test the physical properties of the soil in the field and laboratory.  If necessary, do additional skid tests of the floor.

Phase #4 Data analysis and interpretation

Analyse data and test results and identify conditions that could account for the patient’s symptoms.  List from most likely to least likely – the differential diagnosis.  Look at the most probable diagnosis at the top of the list then go back to Phase #3 and order more tests to confirm depending on how confidant you are.

Study the data, look at how different pieces of data relate and support one another and relate to possible causes of the personal injury or the crane or building collapse.  Identify the probable cause(s) of the injury or collapse.  If necessary, return to the site to check and confirm earlier findings.

Phase #5 Treatment

In medicine, prescribe a treatment of the condition with medicines, life style changes, diet, etc.  Monitor the condition and if improves good.  If no improvement, consider the dosage of medicines and the extent of other changes.  If none or not much go back to the previous phase and reconsider the differential diagnosis.  Treatment is the prescription, the plan in SOAP. (Ref. 3)

In forensic work, report the most probable cause of the accident or failure.  Recommend how the damage can be fixed and the cause of the accident or failure eliminated.

***

I see the differential diagnosis process as an elaboration of the SOAP process that is also followed in medicine: (Ref. 3)

1. Gather Subjective data.  Take a history from the patient in medicine and a briefing on the problem in engineering.  Reflect on why the patient is hurting and the different categories of structural failure in engineering.

2. Get some Objective data.  Like blood work and X-rays in medicine and measurements and field and laboratory tests in forensic investigation.

3. Analyse the data.  Study, identify and list the different medical conditions indicated by the data that could account for the patient’s symptoms.  And in forensic work, the different causes that could account for the personal injury or the crane or bridge collapse.  The list is the differential diagnosis in medicine and the possible causes in a forensic investigation, going from the most likely cause at the top to the least likely at the bottom.

4. Prescribe treatment.  For example, identify life style changes, diet and/or medications to fix the medical condition and make the symptoms disappear.  In forensic work recommend how the damage can be repaired and the cause removed.

***

Can you imagine the embarrassment to the medical doctor and the pain for the patient if s/he prescribed treatment based on the results of Phase #1 of the differential diagnosis process and he was wrong and the patient dies?  Everybody gets in trouble.

Fortunately, that doesn’t happen often in medicine.  Unfortunately it happens at times in forensic work – the client runs with the expert’s initial thoughts on cause.  A few years ago, an expert noted the occasional pressure on an expert during a forensic investigation to find support for those initial thoughts.

Summary

So, the next time you’re getting a medical check-up think about the forensic expert and hope the doctor doesn’t go with his initial thoughts on the cause of your symptoms.  And if you’re the forensic expert, go out of your way to help your client, the injured party, understand that an initial thought on cause is not necessarily a final diagnosis.  It’s at the front end of the subjective-data-collection-stage and a soft thought.

References

1. Dr. Google
2. Personal conversation with Dr. J. Nasser, Halifax, a retired ear, nose and throat surgeon and a former dentist
3. Using SOAP notes in forensic engineering investigation.  Posted February 6, 2014