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Categorical vs. QuantitativeVariables
Identifying the Difference
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Introduction to Statistics--Variables
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Variables Come in 2 Varieties
1. Categorical (or __________)
2. Quantitative (or __________)
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Introduction to Statistics--Variables
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Categorical Variable Characteristics
• Recorded usually with words
• Records which of several groups an individual belongs to
• Count data in each group, but you logically should not average it
• Can calculate %age distributions
• Includes all yes/no questions
• Graphing: best illustrated with a pie chart(but could also be a bar graph)
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Introduction to Statistics--Variables
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Quantitative Variable Characteristics
• Possible responses are numerical in nature
• Includes values for which it makes sense to do operations like adding, totaling and averaging
• Includes answers to how much/how many questions
• Always includes ‘units’
• Graphing: best illustrated with a bar chart
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Introduction to Statistics--Variables
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2 Types of Quantitative Variables
1. __________ If the Q variable is a set of isolated points on thenumber line, we call it this. (i.e., it’s a number but it only comes in certain values) Usually a variable that can be ‘counted’.
2. __________ If the Q variable forms an entire interval along the number line, we call it this. (i.e., it’s a number & it can be any value) Usually a variable that can be ‘measured’.
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Introduction to Statistics--Variables
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Diagram of Variable Types
Categorical(Qualitative)
Variables Discrete
Quantitative(Numerical)
Continuous
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Introduction to Statistics--Variables
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Categorical or QuantitativeIf Categorical, one possible category?
If Quantitative, Continuous or Discrete? Units?
1) Length of a pen?
2) Type of pen?
3) Number of pens in box?
4) Maker of pen?5) Flow of ink in ml/sec?
6) Color of pen’s ink?
7) Point size of pen?
Subject of a book? Number of pages in the
book? Area of each page of
book? Number of letters on a
page? Number of weeks on
best seller list?
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Introduction to Statistics--Variables
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Categorical or QuantitativeIf Categorical, one possible category?
If Quantitative, Continuous or Discrete? Units?
1) Style of pants?
2) Color of pants?3) Number of pairs of
pants you own?
4) # of pockets on pants?
5) Size of pants?
6) Maker of the pants?7) Length of inseam on the
pants?
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Introduction to Statistics--Variables
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Reviewing Variable Types
1. __________ (or __________)
2. __________ (or __________)
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Introduction to Statistics--Variables
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Reviewing ________ Variables
• Possible responses are ________ in nature• Includes values for which it makes sense to do
operations like ________, ________ and ________.
• Includes answers to ________/________ questions
• Includes ‘________’• Usually—best illustrated with a ________, but
___________________________________.
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Introduction to Statistics--Variables
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2 Types of __________ Variables
1. __________ If the Q variable forms an entire interval _______________,
we call it this. (i.e., it’s a number & it can be any value).
2. __________ If the Q variable is a set of isolated ___________
_________, we call it this. (i.e., it’s a number but it only comes in certain values)
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Introduction to Statistics--Variables
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Classwork & Homework
• Use the terms you’ve learned to analyze the types of variables you encounter in the samples
• Answer some the ‘usual’ questions about the nature of this survey using the data and your powers of analysis.
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Introduction to Statistics--Variables
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Answers to Fill in Blanks
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Finding Individuals & Variables in a List
State Region Population Males Females
AlabamaAlaska
SouthWest
15.6m5.4m
8.3m2.5m
7.2m2.9m
Arizona West 10.2m 5.1m 5.1m
Introduction to Statistics--Variables
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Individuals in Sample—Usually in 1st ColumnVariables—Usually in 2nd and succeeding columns
Number of in Sample = 3Who’s in Sample? Alabama, Alaska, Arizona
Variable = Region = CategoricalVariable = Population = Discrete QuantitativeVariable = Males = Discrete QuantitativeVariable = Females = Discrete Quantitative
Look for Variable Names in Column Headings
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Introduction to Statistics--Variables
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Variables Come in 2 Varieties
1. Categorical (or Qualitative)
2. Quantitative (or Numerical)
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Introduction to Statistics--Variables
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2 Types of Quantitative Variables
1. Discrete If the Q variable is a set of isolated points on the
number line, we call it this. (i.e., it’s a number but it only comes in certain values)
2. ContinuousIf the Q variable forms an entire interval along the number line, we call it this.
(i.e., it’s a number & it can be any value).
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Introduction to Statistics--Variables
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Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete?
1) Length of a pen?
2) Type of pen?
3) Number of pens in box?
4) Maker of pen?5) Flow of ink in ml/sec?
6) Color of pen’s ink?
Quantitative, Continuous
Categorical
Quantitative, Discrete
Categorical
Quantitative, Continuous
Categorical
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Introduction to Statistics--Variables
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Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete?
Subject of a book? Number of pages in the
book? Area of each page of
book? Number of letters on a
page? Number of weeks on
best seller list?
Categorical
Quantitative, Discrete
Quantitative, Continuous
Quantitaitve, Discrete
Quantitative, Discrete
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Introduction to Statistics--Variables
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Categorical or QuantitativeIf Categorical, one possible category? If Quantitative, Continuous or Discrete?
1) Style of pants?
2) Color of pants?3) Number of pairs of
pants you own?
4) # of pockets on pants?
5) Size of pants?
6) Maker of the pants?7) Length of inseam on the
pants?
Categorical
Categorical
Quantitative, Discrete
Quantitative, Discrete
Quantitative, Discrete
Categorical
Quantitative, Continuous
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Introduction to Statistics--Variables
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Reviewing Variable Types
1. Categorical (or Qualitative)
2. Quantitative (or Numerical)
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Introduction to Statistics--Variables
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Reviewing Quantitative Variables
• Possible responses are numerical in nature• Includes values for which it makes sense to do
operations like adding, totaling and averaging.• Includes answers to how much/how many
questions• Includes ‘units’• Usually—best illustrated with a bar graph, but
pie chart is also possible.
![Page 22: Categorical vs. Quantitative Variables Identifying the Difference](https://reader033.vdocuments.us/reader033/viewer/2022051415/56649d705503460f94a52def/html5/thumbnails/22.jpg)
Introduction to Statistics--Variables
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Reviewing Categorical Variables• Recorded usually with words
• Records which of several categories an individual belongs to
• Count data in each group, but you logically should not average it
• Can calculate percentage distributions
• Includes all yes/no questions
• Usually—best illustrated with a pie chart.
![Page 23: Categorical vs. Quantitative Variables Identifying the Difference](https://reader033.vdocuments.us/reader033/viewer/2022051415/56649d705503460f94a52def/html5/thumbnails/23.jpg)
Introduction to Statistics--Variables
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2 Types of Quantitative Variables2. Continuous If the Q variable forms an entire
interval along the number line, we call it this.
(i.e., it’s a number & it can be any value).
2. Discrete If the Q variable is a set of isolated points on thenumber line, we call it this.
(i.e., it’s a number but it only comes in certain values)