STAT2003 Chapter 1-3: Introduction to Statistics and Categorical Data
Ch. 1. Stats Starts Here , Ch. 2. Displaying and Describing Categorical Data, Ch. 3. Displaying
and Summarizing Quantitative Data
Covers: 8/28, 8/30, 9/1 (3 Lectures, Week 1)
Ch 1. Stats Starts Here
Making Sense of Information
● Data
○ Any collection of numbers, characters, images, or other items that give info.
○ Can vary, a variety of outcomes could exist from surveys and experiments
○ Ex. of its uses:
■ Facebook collects data about you
● Personal info: age, gender, education, etc.
● Interests ased o hat ou like
● If you follow an ad, facebook has even more data
■ Statistics are used to determine which ads you see
■ Big Data
■ Texting while driving:
● Questions asked:
Is texting while driving dangerous?
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Texting has grown drastically in the last five years.
Driving fatalities have gone down significantly in the last five
years.
Is texting while driving safe?
How might you decide?
● Measured reaction times of sober, drunk, and texting drivers in
simulated driving emergencies
○ result: those texting had the slowest reactions.
● Statistics
○ Helps us makes sense of the data and how the data vary!
Organizing Data
● How data is presented can make a lot of difference. Compare the two pictures below.
Which one makes more sense?
● The six Ws
○ Who: Describe the subjects who were surveyed.
○ What: Determine what is being measured.
○ When: When was the research conducted?
○ Where: Where was the research conducted?
○ Why: What was the purpose of the survey or experiment?
○ HoW: Describe how the survey or experiment was conducted.
● Who and What:
○ Respondents: Individuals who answer the survey
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■ Ex. Customers at Amazon
○ Subjects or participants: Whatever is being experimented on
■ Ex. Patients who receive the new medication
○ Experimental Units: The object of the experiment when it is not a person
■ Ex. Rats that are in a maze
○ Records: Rows in a database
■ Eah peso’s puhase histo at Aazo
● Sample and Population
○ The goal is to describe the population
○ This is usuall ipatial o ipossile so….
○ A sample is used to make inferences about the population so it should be
representative of the population
● Think, Show and Tell
○ THINK about the information you want to know/acquire
○ SHOW your results by displaying the data in a professional/precise/accurate
manner
○ TELL your story by describing what can be concluded from the data that was
collected.
Variables
● Categorical Variable: Tells us what group or category and individual.
○ Synonyms: nominal and qualitative
○ Ex. favorite color, birth country, area code
○ Drawback of these variables is that they are challenging to analyze by means of
computation
● Quantitative Variable: Contains measured numerical values with measurement units
○ Typically the amount or degree of something
○ Unit examples: ounces, dollars, degrees Fahrenheit, kilograms
● Categorical or Quantitative?
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Document Summary
Covers: 8/28, 8/30, 9/1 (3 lectures, week 1) Any collection of numbers, characters, images, or other items that give info. Can vary, a variety of outcomes could exist from surveys and experiments. If you follow an ad, facebook has even more data. Statistics are used to determine which ads you see. Texting has grown drastically in the last five years. Driving fatalities have gone down significantly in the last five years. Measured reaction times of sober, drunk, and texting drivers in simulated driving emergencies. Result: those texting had the slowest reactions. Helps us makes sense of the data and how the data vary! How data is presented can make a lot of difference. Who: describe the subjects who were surveyed. How: describe how the survey or experiment was conducted. Subjects or participants: whatever is being experimented on. Experimental units: the object of the experiment when it is not a person. The goal is to describe the population.
