Ratio Statistics
This table displays the summary statistics you requested, for each group defined by the grouping variable.
The median is a measure of central tendency that tells you the "typical" ratio between the last appraised value and sale value. By comparing the median ratio for each township, you can determine which township's housing values have changed the most.
- Because its median ratio is closest to 1, the typical value of a Northern township house has changed the least.
- Contrariwise, Southern township's housing values have changed the most.
The coefficient of dispersion (COD) is a general measure of the variability in the ratios. Larger COD values indicate greater variability.
- Northern township appraisal/sale value ratios show the least variability, according to COD.
- Southern township ratios show the greatest variability, with a COD of 1.99.
The within % of median coefficient of concentration (COC) also measures variability, but is easier to interpret because it simply reports the percentage of values within a certain percentage of the median. Larger values of this statistic indicate less variability. The within 20% COC confirms that the ratios in Northern township had the least variability.
The clerk's office is particularly interested in updating the assessments for homes whose value has changed by more than 20% of the last appraised value. Though the median, COD, and within 20% COC are helpful measures of the distribution of ratios, they cannot help you determine how many homes are "of interest" to the clerk's office. The percent between coefficient of concentration (COC) is a flexible measure that allows you to determine the percentage of ratios than fall within an arbitrary interval. By requesting the COC for the interval between 0.8 and 1.2, you will be able to determine the percentage of homes in each township whose values have changed by less than 20% of the last appraised value.
- Nearly 96% of the home values for the recent sales in Northern township have changed less than 20% since their last appraisal. Thus, only 4.1% of the homes are of interest to the clerk's office. It's probably safe to put off re-appraisal of homes in that township for another time.
- 63.9% of the recently sold homes in Southern township are of interest to the clerk's office. An assessor for Northern township can be reassigned to Southern.