coursebook notes - chapter 5 - data and variables

Question 1

what is the dplyr package for?

Answer 1

data manipulation

Question 2

what is the ggplot2 package for?

Answer 2

making plots

Question 3

What are the 2 types of variables in a data set?

Answer 3

numerical and categorical

Question 4

what are the 2 further categories of numerical variables?

Answer 4

interval and ratio

Question 5

what are the 2 further categories of categorical variables?

Answer 5

ordinal and nominal

Question 6

What is a nominal variable?

Answer 6

refers to categories that have no natural ordering relative to one another

Question 7

what is ordinal data?

Answer 7

observations can be assigned some meaningful order, but where the exact distance between variables is unknown

Question 8

what are interval variables?

Answer 8

take values on a consistent numeric scale, but where the scale starts at an arbitrary point

Question 9

what are ratio scale variables?

Answer 9

have a true zero and a known and consistent mathematical relationship between any points on the measurement scale

Question 10

What is the definition of accuracy?

Answer 10

how close a measurement is to the true value of whatever it is you are trying to measure

Question 11

What is the definition of precision?

Answer 11

how repeatable a measure is, irrespective of whether it is close to the actual value