6:52pm Dec 3 at 6:52pm
Scales of measurement are described as placing numbers into different categories. The four scales of measurement are ordinal, nominal, interval, and ratio. The Ordinal scale helps rank individual attributes comparing them to elements in the group. There is no unit of measurement for this scale. An example of this would be a tree farm, looking at all the trees, why is one tree taller than others or wider. However, there is no actual measurement or number of the height or width of the trees. It is pretty much greater or less than. Not exactly specific measurements.
The nominal scale is a categorical variable, mutually exclusive numbers with no categories or orders. These are not used for measuring quantities. It produces quantitative results. An example of this would be a cat or dog, you can’t have a catdog. There is no mixing or other outcomes.
Interval scale categories the data in groups. The difference between the two values is meaningful. An example of this would be SAT scores, it places you into a group pass/fail or average score and excels score. Will you get into a community college or Havard?
Ratio scale is the highest degree of measurement with numerous interval scales, a true zero and equals between two points (Thorndike,2009). The population would be an example of this scale.
Central tendency is a single value that defines a set of data to identify the mean.It can provide an overview of statistics as well. The average is the most common along with mode and median. “The mode, arithmetic mean, and median seldom has exactly the same value, but usually they do not differ greatly. (Thorndike, 2009)” All three of these are very closely related, there will not be one that is much different from the rest. Distributions that are close to one another will be symmetrical, the median or average will group together well. With distributions that are skewed the median will more than likely be affected less by a handful of cases due to the long tail (Thorndike, 2009).
References:
Thorndike, R. M., & Thorndike-Christ, T. M. (2009).
Measurement and evaluation in psychology and education
(8th ed.). Upper Saddle River, NJ: Prentice Hall.
Frost, J. (2020). Measures of Central Tendency: Mean, Median, and Mode - Statistics By Jim. Retrieved 30 November 2020, from
https://statisticsbyjim.com/basics/measures-central-tendency-mean-median-mode/