In a ratio study, what does a coefficient of dispersion measure?
Correct Answer
B) The uniformity of ratios within the group studied
Why this is correct: In assessment ratio studies, the Coefficient of Dispersion (COD) measures the uniformity or equity of assessments. It calculates the average percentage deviation of individual assessment ratios from the median ratio. A low COD indicates uniform treatment; a high COD indicates inconsistent assessments. Why the other choices are wrong: 'The average level of assessment across the group' is measured by the median or mean ratio, not the COD. 'The number of properties included in the sample' is the sample size. 'The correlation between assessed value and price' measures a different statistical relationship (linear association). Exam tip: COD measures uniformity/equity; the median ratio measures the level of assessment.
Why This Is the Correct Answer
Why this is correct: In assessment ratio studies, the Coefficient of Dispersion (COD) measures the uniformity or equity of assessments. It calculates the average percentage deviation of individual assessment ratios from the median ratio. A low COD indicates uniform treatment; a high COD indicates inconsistent assessments. Why the other choices are wrong: 'The average level of assessment across the group' is measured by the median or mean ratio, not the COD. 'The number of properties included in the sample' is the sample size. 'The correlation between assessed value and price' measures a different statistical relationship (linear association). Exam tip: COD measures uniformity/equity; the median ratio measures the level of assessment.
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