# Strengths and weaknesses of the measures of central tendency and dispersion

Let us demonstrate this. The mode is the only appropriate measure of central tendency for data that is nominal in nature, data that does not come from a "yardstick" measurement and that does not have an underlying order.

It is the task of the responsible user to know the kind of data being studied, and the appropriate measures to use for that data. The median is not so affected. The mean can be used for both continuous and discrete numeric data. Those programs are more than happy to compute the mean for any kind of data.

It might even be a decimal value. As the mean includes every value in the distribution the mean is influenced by outliers and skewed distributions.

Even the same person may mark two questions with a 4 and feel quite different about the actual extent of agreement with the two statements. Here is a data set of values: Geometric Mean It is defined as the arithmetic mean of the values taken on a log scale. This is also known as the arithmetic average.

Half of the other values in the list are below 7 and half are above 7. SD is the most sensitive measure of dispersion as it is derived by using every score in the data set ans is not very distorted by extreme scores. Summary for Measures of Central Tendency The measures of central tendency are the mean, the median, and the mode.

Each measure has its strengths and weaknesses. The calculations are correct, but this value, 21, no longer seems representative of the 11 values n the data set. This article has been cited by other articles in PMC. The Median To calculate the median, we need to put the numbers in order and find the middle value.

At the same time, even with a larger data set, outrageously extreme values, such as changing the 17 to awill still make a huge difference in the value of the mean. Nominal measurements merely assign numbers as names. With a large data set with an even number of items each item tends to appear many times.

Therefore, it is appropriate to look at the median of ordinal, interval, and ratio measurements. In the following distribution, the two middle values are 56 and 57, therefore the median equals Repeated samples drawn from the same population tend to have similar means.

Now our data set is: The mean is the most appropriate measure of central tendency if the original data stems from measurements.Measures of. Variability. CHAPTER. 4. Chapter Outline. An Example From the. The Range • Strengths and weaknesses of the range The Interquartile Range • Strengths and weaknesses of the interquartile range Similar to measures of central tendency, there are multiple measures.

Central Tendency- Descriptive statistics that identify which value is most typical for the data set The Mean Adding all of the scores in a data set together and dividing by the number of scores. The measures of central tendency are not adequate to describe data. Two data sets can have the same mean but they can be entirely different. Thus to describe data, one needs to know the extent of variability. This is given by the measures of dispersion. Range, interquartile range, and standard.

A measure of central tendency (also referred to as measures of centre or central location) is a summary measure that attempts to describe a whole set of data with a single value that represents the middle or centre of its distribution.

Measures of Central Tendency. In this session we look at three different measures of central tendency or ‘average’. These are the mean, the median and the mode. Measures of Dispersion. In this session we also look at measures of dispersion that summarise the 'width' of the distribution.

Broadly, there are ranges and variance. Strengths And Weaknesses Of The Measures Of Central Tendency And Dispersion. Sampling and Measures of Central Tendency and Dispersion Introduction: Overall Job Satisfaction (OJS) was the variable selected for this exercise because it lends itself to measures of central tendency and dispersion.

The data are quantitative and .

Strengths and weaknesses of the measures of central tendency and dispersion
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