Looking For Trouble
Estimated values can be reviewed in a variety of ways including scatter plots, GIS mapping and stratification analysis. Extreme data may create visible problems. Sample scatter plot-sale ratios versus effective age: Here the variation in the oldest (+100 years) properties compares reasonably well to the more typical 50 to 60 year ages. Sample GIS mapping: […]
On the Edge
Part 1: In the Land of Extreme Data Extremes challenge valuation models. We have to be conscious of data extremes in the property inventory: They may deserve review. They may deserve exclusion from sales modeling. They may even deserve attention in model variable design or coefficients. Have you ever wondered what local data extremes […]
