In Part 1, we saw that context is important in the use of an algorithm. In Part 2 we note the role of algorithms in modern asset analytics — the data science valuation view. The “problem to be solved” is the context for the use of algorithms. But what are the benefits of algorithmic thinking? […]
Asset Analyst: More than an appraiser? It is clear that the need for personal value opinion is going away. Yet the old appraisal practices and standards require an opinion. The new way is cleaner. Show your work – Just like your third-grade teacher told you. The old standards focus on the appraiser. The new standards […]
What are the elephants in the room? The elephants are our beliefs. These are the beliefs we all assume to be true. Let’s look at the first of our herd of elephants: number 1 – judgment. We often hear it said that no machine can replace human judgment. Or that appraisal will always require someone […]
Can we compare “statistical adjustment” methods to traditional appraisal adjustment practices? ‘Adjustment’ is mentioned only once in USPAP; (Standard 5 on mass appraisal). However, in The Appraisal of Real Estate, “adjust” comes up 687 times! It must be important. Surely, it’s clearly explained. In each use, the context is critical. It states: ‘Adjustment’ builds on […]
We hear about models and algorithms. We are told the appraisal process is a model. And so are the cost, income, and comparison approaches. No big deal. Ok. So now we know there are big models, and sub-models. An appraiser must know how to model. We have also heard about automated valuation models (AVMs). Hmmm. […]
Take a sample or pick comps: different or the same? Most of us grew up first learning descriptive statistics: mean, median, standard deviation and such. Later, we learned that it was usually impossible or too expensive to get all the data, so we got a sample which seemed to be like the whole ‘population’ we […]
Appraisers study some economics. Data training is “pick comps carefully.” AVMs use data. AVMs (Automated Valuation Models) usually use a lot more data, even dozens or hundreds or …. Appraisers usually pick six or seven comps, based on good judgment and training and experience. We are told comparables should be similar and competitive, so they […]
Graphs for analysts and appraisers are how we see. It is difficult to vision a median or clusters or market relationships using just numbers. It is even blurrier when someone uses p-values, R-squared’s, and t-scores, claiming these somehow ‘support’ their personal opinion of value. Bad enough in regular work. Even worse gobbledygook when used as […]
More graphs: in data science, why are they so important? Graphs provide the way for the human brain and the computer to connect. And why is that important? More Computers are really good at certain things. They can handle lots of data and can quickly carry out complex instructions (algorithms) with no mistakes, with perfect […]
Is it time to recognize the importance of EDA in all valuation products? EDA is Exploratory Data Analysis, sometimes called PDA (Preliminary Data Analysis). Who does it? Is it necessary? And why do we care? EDA (Exploratory Data Analysis) is a key part of the modern, data science solution to value and risk. It’s an […]
Modernized Appraisal is a necessary part of coming lending regulation. Some think old methods are just fine. Others think advanced quantitative methods are necessary. What to do? Most of us started out learning about things like median, mean, maximum, minimum, and even standard deviation. “Descriptive statistics” they called it. Our teachers also showed us pretty […]
A valuation model may not be a model valuation. What happened with that sentence? It’s called “equivocation.” Something I learned about in my college English class. What I learned is that a word can be used for different meanings. Equivocation can be used to make language more colorful – to entice, to irritate, or to […]
Errors and mistakes can be “statistical.” They can be modeling Blunders. Or they can be of a third type: misjudging what the data is showing you. As we continue to grow the CAA (Community of Asset Analysts), we find that our body of useful algorithms and shared programs continues to deepen and widen. The accuracy […]
Multiple regression works very well under some conditions. We ask: Are these conditions true in most real property valuations? This is actually a vast topic, so we can only reflect on some of the conditions or assumptions which are required for a multiple regression to be valid. Much (if not all) “advanced” appraiser education makes […]
The seminal appraisal model was espoused by George Schmutz in the 1940’s. His “appraisal process” followed the works of others starting in 1927 with Arthur Mertzke who translated economic principles to the unique economic features of real estate. Those works presented “systematic procedures” for applying the three traditional approaches to value. Editor’s Note: Find Part […]