The document discusses different categories of methods for analyzing data distributions: central tendency, spread, and symmetry. Central tendency describes where data are clustered around the average or center. Spread describes how far data are from the middle. Symmetry describes the overall shape of the distribution. The document provides examples of questions that would require analyzing the central tendency, spread, or symmetry and instructs the reader to identify which one is most relevant. It emphasizes that every distribution has all three characteristics but the analysis may focus on one aspect.
1. What category of method is appropriate for the
research question? Methods dealing with …
Central Tendency? Spread? Symmetry?
2. Central Tendency Tells you about where the data are
clustering or centered in the
distribution (e.g., average, center, middle).
Spread Tells you about how spread out the
data are from the middle. (e.g., spread,
difference, deviation, range, variation, vary
etc.)
Symmetry Tells you about the shape of the
distribution.
3. Note – if before going on you would like to
brush up on what a distribution is – click the link
below:
Link to instruction on distributions
Return to this slide when you are done.
5. Central Tendency
Central Tendency, Spread, or Distribution Shape?
Tells you about where the data are
clustering or centering.
Look for words like, average, mean,
median, most common, center point
etc.
Note – to review what a distribution is go to slide 44 and then return to this slide.
6. Central Tendency
Central Tendency, Spread, or Distribution Shape?
Tells you about where the data are
clustering or centering.
Look for words like, average, mean,
median, most common, center point
etc.
Note – to review what a distribution is go to slide 44 and then return to this slide.
7. Central Tendency
Central Tendency, Spread, or Distribution Shape?
Tells you about where the data are
clustering or centering.
Look for words like, average, mean,
median, most common, center point
etc.
Examples:
What is the average test score?
What is the most frequent score?
What is the median income?
9. Central Tendency, Spread, or Distribution Shape?
Spread Tells you about how spread out the
data are from one another.
Look for words like spread,
difference, deviation, range,
variation, vary, etc.
10. Central Tendency, Spread, or Distribution Shape?
Examples:
How spread out are the test results?
How much does income vary in community X?
What is the difference between the highest and lowest scores?
Spread Tells you about how spread out the
data are from one another.
Look for words like spread,
difference, deviation, range,
variation, vary, etc.
12. Central Tendency, Spread, or Distribution Shape?
Symmetry Tells you about the shape of the
distribution.
Look for words like shape or
expressions like
• Most of the data in the center.
• A few data points to the left or right.
• All data evenly distributed.
• Shape of the distribution is very
peaked.
13. Central Tendency, Spread, or Distribution Shape?
Example:
Are the lab results mostly on the high or low end?
Symmetry Tells you about the shape of the
distribution.
Look for words like shape or
expressions like
• Most of the data in the center.
• A few data points to the left or right.
• All data evenly distributed.
• Shape of the distribution is very
peaked.
14. Important Note
Every data set has central tendency, spread,
and symmetry.
Student Test Score
Anne 35
Bob 31
Carla 43
Daniel 29
Eva 30
15. Important Note
Every data set has central tendency, spread, and
symmetry.
Student Test Score
Anne 35
Bob 31
Carla 43
Daniel 29
Eva 30
In the practices that follow, you
will be directed to focus on one
of these at a time.
17. Central Tendency Tells you about where the data are
clustering or centered in the
distribution (e.g., average, center, middle).
Spread Tells you about how spread out the
data are from the middle. (e.g., spread,
difference, deviation, range, variation, vary
etc.)
Symmetry Tells you about the shape of the
distribution.
19. Problem #1
Question: What is the average number of cyberbullying incidents
among freshmen, sophomores, juniors, and seniors?
20. Problem #1
Question: What is the average number of cyberbullying incidents
among freshmen, sophomores, juniors, and seniors?
Instructions: Which type of description of the distribution
(below) is most relevant to the question (above)?
Central Tendency Spread Symmetry
21. Problem #1
Question: What is the average number of cyberbullying incidents
among freshmen, sophomores, juniors, and seniors?
Central Tendency Spread Symmetry
22. Problem #1
Question: What is the average number of cyberbullying incidents
among freshmen, sophomores, juniors, and seniors?
Central Tendency Spread Symmetry
Tells you about where the data are clustering or centering.
Look for words like, average, mean, median, most common, center point etc.
23. Problem #1
Question: What is the average number of cyberbullying
incidents among freshmen, sophomores, juniors, and seniors?
Central Tendency Spread Symmetry
Tells you about where the data are clustering or centering.
Look for words like, average, mean, median, most common, center point etc.
24. Problem #2
Question: What is the difference between the lowest and
highest score on a survey designed to test the impact of a new
therapy?
25. Problem #2
Question: What is the difference between the lowest and
highest score on a survey designed to test the impact of a new
therapy?
Instructions: Which type of description of the distribution
(below) is most relevant to the question (above)?
Central Tendency Spread Symmetry
26. Problem #2
Question: What is the difference between the lowest and
highest score on a survey designed to test the impact of a new
therapy?
Central Tendency Spread Symmetry
27. Problem #2
Question: What is the difference between the lowest and
highest score on a survey designed to test the impact of a new
therapy?
Central Tendency Spread Symmetry
Tells you about how spread out the data are from one another.
Look for words like spread, difference, deviation, range, variation, etc.
28. Problem #2
Question: What is the difference between the lowest and
highest score on a survey designed to test the impact of a new
therapy?
Central Tendency Spread Symmetry
Tells you about how spread out the data are from one another.
Look for words like spread, difference, deviation, range, variation, etc.
29. Problem #3
Question: The director of a health clinic has asked you to help
her analyze data from the results of patient systolic blood
pressure readings. You decide to compute the mean systolic
pressure to see where the patient results cluster.
30. Problem #3
Question: The director of a health clinic has asked you to help
her analyze data from the results of patient systolic blood
pressure readings. You decide to compute the mean systolic
pressure to see where the patient results cluster.
Instructions: Which type of description of the distribution
(below) is most relevant to the question (above)?
Central Tendency Spread Symmetry
31. Problem #3
Question: The director of a health clinic has asked you to help
her analyze data from the results of patient systolic blood
pressure readings. You decide to compute the mean systolic
pressure to see where the patient results cluster.
Central Tendency Spread Symmetry
32. Problem #3
Question: The director of a health clinic has asked you to help
her analyze data from the results of patient systolic blood
pressure readings. You decide to compute the mean systolic
pressure to see where the patient results cluster.
Central Tendency Spread Symmetry
Tells you about where the data are clustering or centering.
Look for words like, average, mean, median, most common, center point etc.
33. Problem #3
Question: The director of a health clinic has asked you to help
her analyze data from the results of patient systolic blood
pressure readings. You decide to compute the mean systolic
pressure to see where the patient results cluster.
Central Tendency Spread Symmetry
Tells you about where the data are clustering or centering
Look for words like, average, mean, median, most common, center point etc.
34. Problem #4
Question: An entrance exam for mechanical engineers is very
difficult. If it is very difficult you would expect most of the scores
to bunched up on the lower end of the score distribution with a
few high scores. What is the shape of this distribution?
35. Problem #4
Question: An entrance exam for mechanical engineers is very
difficult. If it is very difficult you would expect most of the scores
to bunched up on the lower end of the score distribution with a
few high scores. What is the shape of this distribution?
Instructions: Which type of description of the distribution
(below) is most relevant to the question (above)?
Central Tendency Spread Symmetry
36. Problem #4
Question: An entrance exam for mechanical engineers is very
difficult. If it is very difficult you would expect most of the scores
to bunched up on the lower end of the score distribution with a
few high scores. What is the shape of this distribution?
Central Tendency Spread Symmetry
37. Problem #4
Question: An entrance exam for mechanical engineers is very
difficult. If it is very difficult you would expect most of the scores
to bunched up on the lower end of the score distribution with a
few high scores. What is the shape of this distribution?
Tells you about the shape of the distribution.
Look for words like shape or expressions like
• Most of the data in the center.
• A few data points to the left or right.
• All data evenly distributed.
• Shape of the distribution is very peaked.
Central Tendency Spread Symmetry
38. Problem #4
Question: An entrance exam for mechanical engineers is very
difficult. If it is very difficult you would expect most of the scores
to bunched up on the lower end of the score distribution with a
few high scores. What is the shape of this distribution?
Central Tendency Spread Symmetry
Tells you about the shape of the distribution.
Look for words like shape or expressions like
• Most of the data in the center.
• A few data points to the left or right.
• All data evenly distributed.
• Shape of the distribution is very peaked.
39. What category of method is appropriate for the
research question? Methods dealing with …
Central Tendency? Spread? Symmetry?
Editor's Notes
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.
Symmetry has to do with he shape of a distribution
When the distribution is symmetrical it has most of the values in the middle with equally decreasing values to the left and right of the distribution (as shown to the left).
A distribution is asymmetrical when it does not follow this pattern (see the bottom two images to the left).
You normally will not be asked to assess skew directly but it is an important step in determining the type of spread or central tendency statistics you will run.