What’s a data frame

ex) market survey

• are you married? yes or no ( logical)
• How old are you (numeric)
• what is your opinion on this product? (character)

quick, have a look at your dataset

head() : show the first observations of a data frame

tail() : prints out the last observation in your dataset

variable in datase

Have a look at the structure

str()

• total # of observation
• total $ of variables
• a full list of the variables names
• the data type of the variables names
• the first observations