Which leaves us at pretty much square one. Comp selection should take care of the 75% to 85%, leaving the appraiser to rank the value influence of the remainder features...which we already do with a much less formal methodology. IMO a well crafted regression model is likely to be more credible.
No you truly don't understand, there is often a VERY much smarter way to do things. Do you, for example, understand the elegance, simplicity and clarity of how Eratosthenes estimated that circumference of the Earth over 2000 years ago? It was actually very simple geometry. It was brilliant and simple. He was off by only 3% in 200BC, Columbus was off by 25% 1700 years later, it was only in the late 18th century that any one else came close.
Once you understand it, it is very hard to understand how no one accepted his argument. Let me briefly describe, although it would be very easy with a chalkboard: There is a well in Syene, Egypt (near the current Aswan dam) that one day a year has the bottom completely lit by the sun, i.e. the sun is directly over the well. That means if you drew a line from the Sun to the center of the Earth it would go through Syene. At that exact time, Eratosthenes noted than in Alexandrea, about 500 miles directly north, the sun created a shadow from tall objects that was at an angle that was 1/50th of a circle. Because of geometric symmetry, that meant that the angle from the center of the Earth to Syene and Alexandria was also 1/50th of a circle. Therefore the circumference of the Earth was 50 times the distance from Syene to Alexandria. If you go on Google Earth and draw a line (Path tool) from Aswan to Alexandria, you will get a distance of about 516 miles. 50x 516 miles = 25,800 miles. The Earth's circumference is 24,901. That is a 3.6% difference.
"How an Ancient Greek Measured the Size of Earth "
"Our first mentor of measurement did something that was probably thought by many in his day to be impossible. An ancient Greek named Eratosthenes (ca. 276-194 B.C.) made the first recorded measurement of the circumference of Earth. If he sounds familiar, it might be because he is mentioned in many high school trigonometry and geometry textbooks. Eratosthenes didn’t use accurate survey equipment, and he certainly didn’t have lasers and satellites. He didn’t even embark on a risky and probably lifelong attempt at circumnavigating Earth. Instead, while in the Library of Alexandria, he read that a certain deep well in Syene, a city in southern Egypt, would have its bottom entirely lit by the noon sun one day a year. This meant the sun must be directly overhead at that point in time. But he also observed that at the same time, vertical objects in Alexandria (almost straight north of Syene) cast a shadow. This meant Alexandria received sunlight at a slightly different angle at the same time. Eratosthenes recognized that he could use this information to assess the curvature of Earth. He observed that the shadows in Alexandria at noon at that time of year made an angle that was equal to an arc of one-fiftieth of a circle. Therefore, if the distance between Syene and Alexandria was one-fiftieth of an arc, the circumference of Earth must be 50 times that distance. Modern attempts to replicate Eratosthenes’s calculations vary by exactly how much the angles were, conversions from ancient units of measure, and the exact distances between the ancient cities, but typical results put his answer within 3% of the actual value.1 Eratosthenes’s calculation was a huge improvement over previous knowledge, and his error was less than the error modern scientists had just a few decades ago for the size and age of the universe. Even 1,700 years later, Columbus was apparently unaware of or ignored Eratosthenes’s result; his estimate was fully 25% short. (This is one of the reasons Columbus thought he might be in India, not another large, intervening landmass where I reside.) In fact, a more accurate measurement than Eratosthenes’s would not be available for another 300 years after Columbus. By then, two Frenchmen, armed with the finest survey equipment available in late-eighteenth-century France, numerous staff, and a significant grant, finally were able to do better than Eratosthenes.2 Here is the lesson for business: Eratosthenes made what might seem an impossible measurement by making a clever calculation on some simple observations. When I ask participants in my measurement and risk analysis seminars how they would make this estimate without modern tools, they usually identify one of the “hard ways” to do it (e.g., circumnavigation). But Eratosthenes, in fact, may not have even left the vicinity of the library to make this calculation. One set of observations that would have answered this question would have been very difficult to make, but his measurement was based on other, simpler observations. He wrung more information out of the few facts he could confirm instead of assuming the hard way was the only way.
Hubbard, Douglas W.. How to Measure Anything: Finding the Value of Intangibles in Business (pp. 10-11). Wiley. Kindle Edition. "
Similarly, the method I use nails down the value contribution of the intangibles for the comparables, i.e. Condition+Quality+Appeal (Style) + possibly View (depending on how the model was created). - Without subjective input by the appraiser. The appraiser's subjective input is limited to the subject property. That greatly reduces error, and makes the argument for opinion of value fairly objective.
The consistent argument that runs through Hubbard's book is that there is very often a much smarter way to estimate or measure intangibles. Read his book.
