inferential and descriptive statisticsexplanation

1. Inferential and Descriptive
Statistics
Learning Module: Explanation

2. Welcome to this learning
module!

3. In this module you will learn
the difference between

4. Inferential and Descriptive
statistics!

5. In later modules you will then
determine when a question
should be answered with one
or the other.

6. First, Descriptive statistics!

7. Simply put, descriptive statistics
describe the features of a data set
using numerical measures.

8. Simply put, descriptive statistics
describe the features of a data
set using numerical measures.
And that’s it!

9. Simply put, descriptive statistics
describe the features of a data
set using numerical measures.
And that’s it!
Here’s an example

10. Meet Mrs. Rohini,

11. a fifth Grade teacher
having a parent teacher
conference.

12. The parent has some
questions about her son
Rohit.

13. She will base her
answers off of a class
data set.

14. She will base her
answers off of a class
data set.
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

15. Data
She will base her
answers off of a class
data set.
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

16. Data
Set
She will base her
answers off of a class
data set.
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

17. Here are the parent’s
questions with Mrs.
Graham’s answers
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

18. What was
Rohit’s
score?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

19. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

20. 32
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

21. Out of how
many
possible?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

22. 50
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

23. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
What were
the highest
and lowest
scores?

24. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
Highest 50,
Lowest 31

25. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
What was
the class
average?

26. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
About 42

27. What was
the most
common
score?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

28. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
45

29. Look’s like
Bobby
needs
more study
time!
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

30. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31
That’s
probably a
good idea.

31. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

32. Back to our definition:
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

33. descriptive statistics describe
the features of a data set using
numerical measures
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

34. descriptive statistics describe
the features of a data set using
numerical measures
Data Set
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

35. descriptive statistics describe
the features of a data set using
numerical measures
Data Set
Numerical Measures
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

36. descriptive statistics describe
the features of a data set using
numerical measures
Data Set
Numerical Measures
Highest to Lowest Score – THE RANGE
Most Common Score – THE MODE
Average Score – THE MEAN
Etc.
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

37. • While descriptive statistics focus on describing a
data set,
• Inferential statistics aims to draw conclusions
about a larger group (called a population),
• based on what is happening with a smaller group
(called a sample).
• Inferential statistics studies a statistical sample,
and from this analysis is able to say something
about the population from which the sample
came.
Now for Inferential statistics!

38. • While descriptive statistics focus on
describing a data set, ics aims to draw
conclusions about a larger group
(called a population),
• based on what is happening with a
smaller group (called a sample).
• Inferential statistics studies a statistical
sample, and from this analysis is able
to say something about the population
from which the sample came.

39. • While descriptive statistics focus on
describing a data set,
• Inferential statistics aims to draw
conclusions or INFER about a larger group
(called a population),
• based on what is happening with a smaller
group (called a sample).
• Inferential statistics studies a statistical
sample, and from this analysis is able to
say something about the population from
which the sample came.

40. • While descriptive statistics focus on describing a
data set,
• Inferential statistics aims to draw conclusions or
INFER about a larger group (called a population),
• based on what is happening with a smaller group
(called a sample).
• Inferential statistics studies a statistical sample,
and from this analysis is able to say something
about the population from which the sample
came.

41. • While descriptive statistics focus on describing a
data set,
• Inferential statistics aims to draw conclusions or
INFER about a larger group (called a population),
• based on what is happening with a smaller group
(called a sample).
• INFERential statistics studies a statistical sample,
and from this analysis is able to say something
about the population from which the sample
came.

42. Same example, but here come a
series of inferential questions
from the parent.

43. How does your
class compare
with other 5th
grade classes:
In the school?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

44. About the
same
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

45. What about other
5th grade classes:
In the district?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

46. A little
better
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

47. What about other
5th grade classes:
In the State
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

48. We are
higher
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

49. What about other
5th grade classes:
In the Country
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

50. We are
much
higher
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

51. Looks like
your class
does not
represent
the national
population
and is
probably
doing better.
Maybe Bobby
doesn’t have to
study as much?
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

52. Maybe.
Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

53. Mrs. Rohini’s 5th
Grade Class
Scores on Spelling
Test
Bhagya 43
Balaram 45
Rohit 32
Bhoomi 45
Basavaraj 38
Benakappa 45
Boregouda 50
Bharati 45
Busheer 31

54. A descriptive study examines the data from
everyone in a group or population.
A descriptive study cannot generalize to other
like groups or populations.
An inferential study examines the data from a
sample and then generalizes the conclusions
about that group to a larger population.
In summary -

55. A descriptive study examines the data from
everyone in a group or population.
A descriptive study cannot generalize to other
like groups or populations.
An inferential study examines the data from a
sample and then generalizes the conclusions
about that group to a larger population.

56. A descriptive study examines the data from
everyone in a group or population.
A descriptive study cannot generalize to other
like groups or populations.
An inferential study examines the data from a
sample and then generalizes the conclusions
about that group to a larger population.

57. A descriptive study examines the data from
everyone in a group or population.
A descriptive study cannot generalize to other
like groups or populations.
An inferential study examines the data from a
sample and then generalizes the conclusions
about that group to a larger population.

58. A descriptive study examines the data from
everyone in a group or population.
A descriptive study cannot generalize to other
like groups or populations.
An inferential study examines the data from a
sample and then generalizes the conclusions
about that group to a larger population.
Note – inferential and descriptive studies use the
SAME statistics (e.g., mean, range, mode, etc.),
but as you can see – for DIFFERENT reasons!