Determining whether to use
Inferential and Descriptive Statistics
Learning Module: Explanation
Welcome to this learning
module!
In this module you will learn
the difference between
Inferential and Descriptive
statistics!
In later modules you will then
determine when a question
should be answered with one
or the other.
First, Descriptive statistics!
Simply put, descriptive statistics describe the
features of a data set using numerical measures.
Simply put, descriptive statistics describe the
features of a data set using numerical measures.
And that’s it!
Simply put, descriptive statistics describe the
features of a data set using numerical measures.
And that’s it!
Here’s an example
Meet Mrs. Graham,
a fifth Grade teacher
having a parent teacher
conference.
The parent has some
questions about her son
Bobby.
She will base her
answers off of a class
data set.
She will base her
answers off of a class
data set.

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
She will base her
answers off of a class
data set.

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

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

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Data

Set
Here are the parent’s
questions with Mrs.
Graham’s answers

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What was
Bobby’s
score?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

32
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Out of how
many
possible?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

50
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What were
the highest
and lowest
scores?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Highest 50,
Lowest 31
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What was
the class
average?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

About 42
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What was
the most
common
score?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

45
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Look’s like
Bobby
needs
more study
time!
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

That’s
probably a
good idea.
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
Back to our definition:

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
descriptive statistics describe
the features of a data set using
numerical measures

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
descriptive statistics describe
the features of a data set using
numerical measures

Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Data Set
descriptive statistics describe
the features of a data set using
numerical measures
Numerical Measures
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Data Set
descriptive statistics describe
the features of a data set using
numerical measures
Numerical Measures
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Highest to Lowest Score – THE RANGE

Bella

43

Most Common Score – THE MODE

Betty

45

Average Score – THE MEAN

Bobby

32

Etc.

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Data Set
Now for Inferential statistics!

• 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.
• 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.
• 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.
• 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.
• 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.
Same example, but here come a
series of inferential questions
from the parent.
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

How does your
class compare
with other 5th
grade classes:
In the school?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

About the
same
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What about
other 5th
grade
classes:
In the
district?
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

A little
better
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What about
other 5th
grade
classes:
In the State
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

We are
higher
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

What about
other 5th
grade
classes:
In the
Country
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

We are
much
higher
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Looks like
your class
Maybe
does not
Bobby
represent
doesn’t
the national
have to
population
study as
and is
much?
probably
doing better.
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31

Maybe.
Mrs. Graham’s
5th Grade Class

Scores on Spelling
Test

Bella

43

Betty

45

Bobby

32

Bonnie

45

Booker

38

Boston

45

Botania

50

Boyle

45

Bunder

31
In summary -

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.
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.
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.
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.
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!

1a difference between inferential and descriptive statistics (explanation)

  • 1.
    Determining whether touse Inferential and Descriptive Statistics Learning Module: Explanation
  • 2.
    Welcome to thislearning module!
  • 3.
    In this moduleyou will learn the difference between
  • 4.
  • 5.
    In later modulesyou will then determine when a question should be answered with one or the other.
  • 6.
  • 7.
    Simply put, descriptivestatistics describe the features of a data set using numerical measures.
  • 8.
    Simply put, descriptivestatistics describe the features of a data set using numerical measures. And that’s it!
  • 9.
    Simply put, descriptivestatistics describe the features of a data set using numerical measures. And that’s it! Here’s an example
  • 10.
  • 11.
    a fifth Gradeteacher having a parent teacher conference.
  • 12.
    The parent hassome questions about her son Bobby.
  • 13.
    She will baseher answers off of a class data set.
  • 14.
    She will baseher answers off of a class data set. Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 15.
    She will baseher answers off of a class data set. Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Data
  • 16.
    She will baseher answers off of a class data set. Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Data Set
  • 17.
    Here are theparent’s questions with Mrs. Graham’s answers Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 18.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What was Bobby’s score?
  • 19.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 20.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 32
  • 21.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Out of how many possible?
  • 22.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 50
  • 23.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What were the highest and lowest scores?
  • 24.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Highest 50, Lowest 31
  • 25.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What was the class average?
  • 26.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 About 42
  • 27.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What was the most common score?
  • 28.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 45
  • 29.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Look’s like Bobby needs more study time!
  • 30.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 That’s probably a good idea.
  • 31.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 32.
    Back to ourdefinition: Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 33.
    descriptive statistics describe thefeatures of a data set using numerical measures Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 34.
    descriptive statistics describe thefeatures of a data set using numerical measures Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Data Set
  • 35.
    descriptive statistics describe thefeatures of a data set using numerical measures Numerical Measures Mrs. Graham’s 5th Grade Class Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Data Set
  • 36.
    descriptive statistics describe thefeatures of a data set using numerical measures Numerical Measures Mrs. Graham’s 5th Grade Class Scores on Spelling Test Highest to Lowest Score – THE RANGE Bella 43 Most Common Score – THE MODE Betty 45 Average Score – THE MEAN Bobby 32 Etc. Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Data Set
  • 37.
    Now for Inferentialstatistics! • 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.
  • 38.
    • While descriptivestatistics 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.
  • 39.
    • While descriptivestatistics 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 descriptivestatistics 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 descriptivestatistics 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, buthere come a series of inferential questions from the parent.
  • 43.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 How does your class compare with other 5th grade classes: In the school?
  • 44.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 About the same
  • 45.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What about other 5th grade classes: In the district?
  • 46.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 A little better
  • 47.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What about other 5th grade classes: In the State
  • 48.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 We are higher
  • 49.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 What about other 5th grade classes: In the Country
  • 50.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 We are much higher
  • 51.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Looks like your class Maybe does not Bobby represent doesn’t the national have to population study as and is much? probably doing better.
  • 52.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31 Maybe.
  • 53.
    Mrs. Graham’s 5th GradeClass Scores on Spelling Test Bella 43 Betty 45 Bobby 32 Bonnie 45 Booker 38 Boston 45 Botania 50 Boyle 45 Bunder 31
  • 54.
    In summary - Adescriptive 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.
  • 55.
    A descriptive studyexamines 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 studyexamines 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 studyexamines 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 studyexamines 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!