STATA 11 for Windows SAMPLE SESSION - Food Security Group ...

Stata 11 Sample Session Section 3 – Tables and other Types of Analysis
responses are requested, four variables must be used to
code the responses. The set of possible responses are
assigned sequential values and the same set of values are
used for each of the 4 variables. The respondent must
record a different value in each of the 4 variables. These
types of variables are called multiple response variables.
Question 35 in the household questionnaire is an example
of a multiple response question. It asks about crops grown
principally to be sold. Each household is asked to specify
up to three main crops which are coded into variables
h35a, h35b, and h35c. Codes are provided for five of the
most common crops. The question is left open-ended,
however, since a code of 6 is allowed for a crop not on the
list. The name of the crop is written down on the
questionnaire and later assigned a code.
Because the question was open ended, more categories
were added to these variables than what appears in the
annex. After the data are collected, the researcher assigns a
code to each of the crops specified for "6-other" - this
procedure is called “post-coding”. Codes and value labels
are entered into the data file and the data changed from the
value of 6 to the appropriate code. As you will see, using
the tab1 command, eleven different crops were specified
for question 35.
Stata does not have an official command that will tabulate
data collected in this format. We can do frequencies of
each variable or develop commands to pull out specific
information. There is a user-written “ado” command called
tabw (Peter Sasieni, STB-25; Stata 3.1). For each variable
in a list of 2 variables, this command will tabulate the
number of times it takes on the values 0, 1, ..., 9; the
number of times it is missing; and the number of times it is
equal to some other value. String variables are not tabulated
but are identified at the end of the displayed table. To
download this ado file, connect to the Stata website.
1. Click on Help then SJ and User Written
Programs.
2. In the Viewer click on STB
3. Scroll down to stb25. and click.
4. Click on sg36 ‘Tabulating the counts of multiple
categorical variables”. In this screen, click on (click
here to install)
5. The program will be installed in the directory:
C:\ado\plus\t
6. To use the program, in the Command window type
97
tabw h35a h35b h35c