Tuesday, September 19
In the past two days, we have discussed many of the ground-work that will be utilized later when discussing advanced statistics. We talked about;
1.) Nonparametric and parametric data
2.) Descriptive and inferential statistics
3.) Frequency Distribution
4.) Measures of Central Tendency
5.) Graphic distribution of data
6.) Standard deviation and variance
Question for thought- Generally, when describing the data, we use the mean as our measure of central tendency. For your post, give an example where the mode or median may explain the data better. Explain the variable you are investigating, and give the circumstances why the mean may not tell you information you could obtain from the median or mode.
1.) Nonparametric and parametric data
2.) Descriptive and inferential statistics
3.) Frequency Distribution
4.) Measures of Central Tendency
5.) Graphic distribution of data
6.) Standard deviation and variance
Question for thought- Generally, when describing the data, we use the mean as our measure of central tendency. For your post, give an example where the mode or median may explain the data better. Explain the variable you are investigating, and give the circumstances why the mean may not tell you information you could obtain from the median or mode.
posted by Dr. Jeffrey Bolt at 5:08 PM
2 Comments:
An example could be teacher evaluation forms. Each student fills out an evaluation form. This form is used to see how well the teachers are doing. If the most frequently reported issues are that the teachers are doing a good job then everything is fine. Now if the report says the exact opposite then some type of action may need to take place. In order to find out this the mode method would be used. The mode reports the most frequently reported results. The mode would be better to use then the mean because the mode could tell you exactly what each student’s thoughts were. The mean would only give you an average of the student’s thoughts.
Melissa Giancola #1
mean:a value that is computed by dividing the sum of a set of terms by the number of terms
median:a value in an ordered set of values below and above which there is an equalnumber of values or which is the arithmetic mean of the two middle values if there is no one middle number
mode:the most frequent value of a set of data
After some research and studying to gain a better understanding of why one might choose the median as a better measure than the mean to describe data and its central tendencies, I learned that it is a good measure when data is skewed. When I realized that “ah ha” moment, I was still grappling to put the idea into a concrete analysis of a tangible variable.
Then I came across the often used term the median income. This is my analysis of why that is a more valuable number than the mean income. Take for instance a community with a large population of the very poor and very small population of the very very rich. Because of the dramatic negative skew that this would create, the mean would be a more true measure of the very very rich more likely than that of the very poor. However the median would dip closer to the bottom half of the population giving a more accurate measure of centrality of the income of the greater majority of the population.
Since nominal data can be described by frequency and the mode is the most frequently recurring response, it is logical that the central frequency can best be described by the mode. An example of this might be the average age of students in this class. One might find that the frequency range is skewed but the mode is more centralized toward the average age.
Mark N. section 2
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