{"id":8737,"date":"2020-10-22T14:06:00","date_gmt":"2020-10-22T17:06:00","guid":{"rendered":"http:\/\/www.ericjorden.com\/blog\/?p=8737"},"modified":"2021-01-15T18:03:24","modified_gmt":"2021-01-15T22:03:24","slug":"the-reliability-of-an-educated-guess-on-the-cause-of-a-failure-or-accident","status":"publish","type":"post","link":"http:\/\/www.ericjorden.com\/blog\/2020\/10\/22\/the-reliability-of-an-educated-guess-on-the-cause-of-a-failure-or-accident\/","title":{"rendered":"The reliability of an educated guess on the cause of a failure or accident"},"content":{"rendered":"\n

I thought to remind readers that some initial hypotheses by experts, educated guesses<\/em>, on the cause of accidents or failures are very reliable – and others are less so. And there’s every gradation in between. This sometimes causes problems for client and expert alike.<\/p>\n\n\n\n

A client decides to take a case or commit to settlement of an insurance claim and all’s good – additional forensic investigation supports the initial hypothesis. <\/p>\n\n\n\n

But often enough the hypothesis must be modified a little or a lot – as per the scientific method <\/em>– and on occasion – rarely – rejected completely. (Ref. 1) This can be difficult.<\/p>\n\n\n\n

There’s also the hope – expert’s feel it as a subtle, unintended pressure – that the expert’s additional investigation will support the initial hypothesis. One colleague commented on this several years ago. <\/p>\n\n\n\n

One solution<\/strong><\/span><\/em> is not to ask for or give an initial hypothesis. I’ve experienced that in the past, not often but on occasion – complete the forensic investigation then give us the findings. <\/p>\n\n\n\n

Another<\/strong><\/span><\/em> might be to assign reliability to a hypothesis on a scale of 1 to 10 so a client has a feel for what s\/he is getting. Or more simply: Is it probable or only possible? Maybe give the possibilities. <\/p>\n\n\n\n

Still another<\/em> solution<\/span>,<\/strong> state clearly<\/em> that in forensic work an initial hypothesis is an educated guess <\/em>based on the available evidence. And additional investigation may change things as per the scientific method that is followed in forensic work. (Ref. 1) Evidence that an expert gets from: <\/p>\n\n\n\n

  1. The client’s briefing on the problem – the accident or failure<\/li>
  2. A document review (text, pictures, video)<\/li>
  3. A visual site assessment – in person or virtually<\/li>
  4. The expert’s past experience<\/li><\/ol>\n\n\n\n

    ***<\/span><\/strong><\/p>\n\n\n\n

    All this came to mind when I saw a large barn on the verge of collapse during a drive in the New Brunswick countryside a few days ago. (Ref. 2) The ridge of the roof sagged an estimated 10 feet from where I was driving. It was something to see.<\/p>\n\n\n\n

    If an expert was retained to assess the cause of a collapsed structure and saw pictures of a structure like this then a very reliable initial hypothesis would jump off the page.<\/p>\n\n\n\n

    ***<\/span><\/strong><\/p>\n\n\n\n

    My thoughts about the reliability of hypotheses were reinforced when a party in Ottawa contacted me a few days ago about the cause of a leaning retaining wall. He sent me 23 pictures of the wall. (Ref. 3)<\/p>\n\n\n\n

    I studied them for an hour and the cause gradually presented based on: <\/p>\n\n\n\n

    1. The nature of the cracks in the wall<\/li>
    2. Water stains on the face of the wall, and their location <\/li>
    3. What was not<\/em> seen on the face of the wall <\/li>
    4. Wall foundation construction as seen at one location <\/li>
    5. The location of the lean with respect to a feature behind the wall, and <\/li>
    6. Past experience with this type of retaining wall construction <\/li><\/ol>\n\n\n\n

      On a scale of 1 to 10 – where 10 is like the reliability of a 10 foot sag in a barn roof – I would give the reliability of my assessment of the cause of the lean an 8. <\/p>\n\n\n\n

      To be really sure, I’ve asked for low level aerial photography of the site with a camera mounted on a kid’s drone – a few dollars of expense for what I’m certain will be clinching evidence.<\/p>\n\n\n\n

      ***<\/span><\/strong><\/p>\n\n\n\n

      Following are my assessments of the reliability of an educated guess,<\/span><\/strong> on a scale of 1 to 10, of the cause of accidents and failures I investigated in the past:<\/p>\n\n\n\n

      1.<\/span><\/strong> I’ve investigated the cause of slip, trip and fall accidents different times. If I had been asked about a slip<\/em> and fall on one particular occasion, I would have given my assessment of cause a 9.<\/p>\n\n\n\n

      2.<\/span><\/strong> A trip<\/em> and fall accident would have got an 8.<\/p>\n\n\n\n

      3.<\/span><\/strong> The cause of a nail gun accident would also have got an 8.<\/p>\n\n\n\n

      4.<\/span><\/strong> Sagging, sloping floors in a high rise would have got a 4 maybe a 5.<\/p>\n\n\n\n

      5.<\/strong> <\/span>The cause of large cracks in the wall of a three story building would get a solid 6. I didn’t even see this wall, not even virtually. I was just told the type of wall and the size of the cracks – not hairline, which was significant – and, right away, I knew their configuration and cause.<\/p>\n\n\n\n

      6.<\/strong> <\/span>The cause of the John Morris Rankine fatal motor vehicle accident would have got a 10, if I had been asked. No question. I drove the test vehicle during my re-enactment of the accident. I’m here to tell the tale which, if I could tell you more, would say a lot about the reliability of an initial hypothesis of cause in this case. Three dimensional video – video from three directions, including early drone-like video from above – was the clincher.<\/p>\n\n\n\n

      ***<\/span><\/strong><\/p>\n\n\n\n

      And so it goes, the up and down reliability of initial hypotheses, and the importance of realizing this. The expert must form an initial hypothesis, an educated guess<\/em>, but, if possible, keep your distance from it till s\/he is well into the forensic investigation and has a good understanding of where it’s heading.<\/p>\n\n\n\n

      References <\/strong><\/p>\n\n\n\n

      1. Google the scientific method<\/em> and read all about it, in fairly jargon-free language<\/li>
      2. Update: You could be excused for thinking that everything is falling down. <\/em> Posted October 13, 2020<\/li>
      3. Morry, C. J., Personal communication, October, 2020<\/li><\/ol>\n\n\n\n

        ***<\/p>\n\n\n\n

        (Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada ejorden@eastlink.ca<\/span><\/strong><\/em>)<\/p>\n\n\n\n

        <\/p>\n\n\n\n

        <\/p>\n","protected":false},"excerpt":{"rendered":"

        I thought to remind readers that some initial hypotheses by experts, educated guesses, on the cause of accidents or failures are very reliable – and others are less so. And there’s every gradation in between. This sometimes causes problems for … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/posts\/8737"}],"collection":[{"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/comments?post=8737"}],"version-history":[{"count":25,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/posts\/8737\/revisions"}],"predecessor-version":[{"id":8985,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/posts\/8737\/revisions\/8985"}],"wp:attachment":[{"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/media?parent=8737"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/categories?post=8737"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.ericjorden.com\/blog\/wp-json\/wp\/v2\/tags?post=8737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}