Categorical vs. Quantitative Variables 4/17/2017 Categorical vs. Quantitative Variables Identifying the Difference 4 Categorical vs. Quantitative.ppt

Variables Come in 2 Varieties Categorical vs. Quantitative Variables 4/17/2017 Variables Come in 2 Varieties Categorical (or __________) Quantitative (or __________) Categorical or Qualitative Quantitative or Numerical Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical Variable Characteristics Categorical vs. Quantitative Variables 4/17/2017 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) Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Quantitative Variable Characteristics Categorical vs. Quantitative Variables 4/17/2017 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 Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

2 Types of Quantitative Variables Categorical vs. Quantitative Variables 2 Types of Quantitative Variables 4/17/2017 __________ 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) Usually a variable that can be ‘counted’. __________ 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’. Discrete Continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Diagram of Variable Types Introduction to Statistics--Variables

Categorical vs. Quantitative Variables 4/17/2017 Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Units? Length of a pen? Type of pen? Number of pens in box? Maker of pen? Flow of ink in ml/sec? Color of pen’s ink? 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? Quant; continuous Categorical Quant, discrete Quant, continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical vs. Quantitative Variables 4/17/2017 Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Units? Style of pants? Color of pants? Number of pairs of pants you own? # of pockets on pants? Size of pants? Maker of the pants? Length of inseam on the pants? Quant; continuous Categorical Quant, discrete Quant, continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Reviewing Variable Types Categorical vs. Quantitative Variables 4/17/2017 Reviewing Variable Types __________ (or __________) Categorical or Qualitative Quantitative or Numerical Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Reviewing ________ Variables Categorical vs. Quantitative Variables Reviewing ________ Variables 4/17/2017 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 ___________________________________. Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

2 Types of __________ Variables Categorical vs. Quantitative Variables 4/17/2017 2 Types of __________ Variables __________ If the Q variable forms an entire interval _______________, we call it this. (i.e., it’s a number & it can be any value). __________ 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) Discrete Continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical vs. Quantitative Variables 4/17/2017 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. Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Answers to Fill in Blanks Categorical vs. Quantitative Variables 4/17/2017 Answers to Fill in Blanks Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Finding Individuals & Variables in a List State Region Population Males Females Alabama Alaska South West 15.6m 5.4m 8.3m 2.5m 7.2m 2.9m Arizona 10.2m 5.1m Individuals in Sample—Usually in 1st Column Variables—Usually in 2nd and succeeding columns Number of in Sample = 3 Who’s in Sample? Alabama, Alaska, Arizona Variable = Region = Categorical Variable = Population = Discrete Quantitative Variable = Males = Discrete Quantitative Variable = Females = Discrete Quantitative Look for Variable Names in Column Headings Introduction to Statistics--Variables

Variables Come in 2 Varieties Categorical vs. Quantitative Variables 4/17/2017 Variables Come in 2 Varieties Categorical (or Qualitative) Quantitative (or Numerical) Categorical or Qualitative Quantitative or Numerical Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

2 Types of Quantitative Variables Categorical vs. Quantitative Variables 4/17/2017 2 Types of Quantitative Variables 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) 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). Discrete Continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical vs. Quantitative Variables 4/17/2017 Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Length of a pen? Type of pen? Number of pens in box? Maker of pen? Flow of ink in ml/sec? Color of pen’s ink? Quantitative, Continuous Categorical Quantitative, Discrete Quant; continuous Categorical Quant, discrete Quant, continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical vs. Quantitative Variables 4/17/2017 Categorical or Quantitative If 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 Quant; continuous Categorical Quant, discrete Quant, continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Categorical vs. Quantitative Variables 4/17/2017 Categorical or Quantitative If Categorical, one possible category? If Quantitative, Continuous or Discrete? Style of pants? Color of pants? Number of pairs of pants you own? # of pockets on pants? Size of pants? Maker of the pants? Length of inseam on the pants? Categorical Quantitative, Discrete Quantitative, Continuous Quant; continuous Categorical Quant, discrete Quant, continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Reviewing Variable Types Categorical vs. Quantitative Variables 4/17/2017 Reviewing Variable Types Categorical (or Qualitative) Quantitative (or Numerical) Categorical or Qualitative Quantitative or Numerical Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Reviewing Quantitative Variables Categorical vs. Quantitative Variables Reviewing Quantitative Variables 4/17/2017 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. Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

Reviewing Categorical Variables Categorical vs. Quantitative Variables 4/17/2017 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. Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt

2 Types of Quantitative Variables Categorical vs. Quantitative Variables 4/17/2017 2 Types of Quantitative Variables 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 the number line, we call it this. (i.e., it’s a number but it only comes in certain values) Discrete Continuous Introduction to Statistics--Variables 4 Categorical vs. Quantitative.ppt