User Guide

44
Chapter 3
How are your cases represented? Controls how the Text Wizard determines where
each case ends and the next one begins.
 Each line represents a case. Each line contains only one case. It is fairly common
for each case to be contained on a single line (row), even though this can be a
very long li
ne for data files with a large number of variables. If not all lines
contain the same number of data values, the number of variables for each case is
determined by the line with the greatest number of data values. Cases with fewer
data value
s are assigned missing values for the additional variables.
 A specifi
c number of variables represents a case.
The specified number of variables
for each case tells the Text Wizard where to stop reading one case and start
reading the next. Multiple cases can be contained on the same line, and cases can
start in th
e middle of one line and be continued on the next line. The Text Wizard
determines the end of each case based on the number of values read, regardless
of the number of lines. Each case must contain data values (or missing values
indicate
d by delimiters) for all variables, or the data file will be read incorrectly.
How many cases do you want to import? You can import all cases in the data file, the
first n cases (n is a number you specify), or a random sample of a specified percentage.
Since th
e random sampling routine makes an independent pseudo-random decision
for each case, the percentage of cases selected can only approximate the specified
percentage. The more cases there are in the data file, the closer the percentage of
cases se
lected is to the specified percentage.