*Documenting data

Documenting data

Data sets and variables can be documented with descriptive labels and notes.

Variable names A name is a sequence of one to 32 letters (A–Z and a–z), digits (0–9), and underscores "_". Stata distinguishes upper and lower case letters, i.e. Var1 and var1 are two different variables A number of names are reserved, namely, double long byte if in int using with str#(str followed by a number) and several others starting with an underscore, avoid to use underscores as the first character of a name.
Variable labels: A string of up to 80 characters used to describe a variable
Value labels labels describing specific values of a variable. In Stata you define a label_name (set of value labels) that is used to define a set of labels to be attached to a particular variable.
Data label: A descriptive label describing a dataset
Notes Notes can be attached to a datasets and variables

Variable, value and data labels

label variable urbc "Urbanization in three categories"	Attach a label to variable urbc
label define classif1 1 "Very poor" 2 "Poor" 3 "Rich" 4 "Very Rich"	Define value label classif1[lblname] a set of values to be attached to a variable
label values gdpc classif1	Attach label set classif1 to variable gdpc
label data "Social indicators for 180 countries in1995"
label list	List the currently defined label names
label define classif1 4 "Very rich", modify	change current label "Very Rich" to "Very rich"
label define classif1 9 missing, add	Add a value label

Quotes are only needed if labels contains spaces (or apostrophes), e.g. "Very rich", no need for quotes is you used Very_Rich.

Notes

note : Data set from the UNDP Website	Attach a note to the date set (several notes can be attached)
note urb : Variable needs to be verified, to many missing values	Attach note to a variable (several notes are possibles)
notes	Lists all notes
notes urb	List notes for variable urb

You have also list notes (notes list), drop notes, replace a note or search notes for a particular string.

Display information on data

describe	Data description of the current data set: all variables (variable name, labels, display formats) and information on the dataset
describe urb infmor	Descriptive information for specific variables
describe urb infmor, fullnames	With long variable names (if defined)
describe using "filename"	Data documentation for a dataset stored in an external file (not currently in memory)
codebook	Full information on the dataset and variables
codebook, compact	Compact information on all variables (with mean, number of valid observations, min/max
codebook pop92-infmor, compact	same, for variables pop92 through infmor

Other useful commands

varmanage Interactive label manager (view and edit)
label drop classif1 delete the definition of a label set name
label language to the the label language (Stata supports labels in several languages): (label language english, rename (rename the current label set to "english"; then label language français, new (create a new label set);