by Alyssa Webb Data can come in many different types but it useless without its context Not all data represented by numbers is numerical ex 1boy 2girl Who What When Where Why and How provides context for data ID: 595096
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Slide1
Chapter 2: Data
by Alyssa WebbSlide2
Data can come in many different types but it useless without it’s context.
Not all data represented by numbers is numerical. (ex: 1=boy, 2=girl)
Who, What, When, Where, Why, and How? provides context for data.If you can’t answer Who and What, then you don’t have data.
What are Data?Slide3
Who
are the cases for which we have collected data.
Respondents- people who answer a surveySubjects/ Participants- people whom we experimentExperimental Units- animals, plants, and inanimate objects
WhoSlide4
The characteristics recorded about each individual are called variables. They should have a name that identifies
What
has been measured.The Why of analysis will shape how we view the variable.
What and WhySlide5
categorical- when a variable names categories and answers how cases fall into these categories
quantitative-when a measured variable with units answers questions about the quantity
Variable TypesSlide6
Where
and
When give us information about the context. How the data are collected can make the difference between insight and nonsense. Where, When, and HowSlide7
Identifier variables- categorical variables with exactly one variable in each category. ex: Social Security number, FedEx tracking number, ect.
Identifying IdentifiersSlide8
A data table is an arrangement of data in which each row represents a case and each column represents a variable.
A case is an individual about whom or which we have the data.
A variable hold information about the same characteristics for many cases.
Data TablesSlide9
For each description of data, identify the
W
’s name, the variables, specify for each variable whether its use indicates it should be treated as categorical or quantitative, and, for any quantitative variable, identify the units in which it was measured (or note that they were not provided). Homework ProblemsSlide10
In the Spring 2001 issue of
Chance
magazine, a psychology professor reported on data he had collected about his sleep patterns. He kept daily records of the number of hours of sleep he got, whether or not he suffered from “early awakening”, whether or not he watched TV in the morning and in the evening, the number of hours he spent standing during the day, and his mood (happy/sad, on a scale from 10-90).problem #23Slide11
Who
- Days
What- Sleep, wake early, TV, hours standing, moodWhen- 2001Where- At homeWhy- To analyze sleep patternsHow- Daily recordingVariable- Sleep, quantitative, hoursVariable- Wake early, categorical
Variable- Tv, categorical
Variable- Hours standing, quantitative, hours
Variable- Mood, quantitative, scale 10-90
problem #23 answerSlide12
The Kentucky Derby is a horse race that has been run every year since 1875 at Churchill Downs, Louisville, Kentucky. The race started as a 1.5 mile race, but in 1896 it was shortened to 1.25 miles because experts felt that 3-year -old horses shouldn’t run such a long race that early in the season (it has been run in May every year but one--1901--when it took place on April 29). Here are the data for the first few recent races.
problem #25Slide13
problem #25Slide14
Who-
Kentucky Derby Races
What- Date, winner, margin, jockey, net proceed to winner, duration, track conditionWhen- 1875 to 2004Where - Churchill Downs, Louisville, KentuckyWhy- To see horse race trendsHow- Official statistics collected at the racesVariable- Year, quantitative, day and year
Variable- Winner, identifier
Variable- Margin, quantitative, horse lengths
Variable- Jockey, categorical
Variable- Net proceeds to winner, quantitative, dollars
Variable- Duration, quantitative, minutes and seconds
Variable- Track condition, categorical
problem #25 answer