handled identically for the rekey operation as in the initial keying, consti-
tuting a completely "blind" rekey effort to provide more accurate estimates
of
keying error.
B.
Error Rates for Fourth Follow-Up Questionnaire Data
For Fourth Follow-Up Questionnaire data entry quality control purposes,
two data entry error rates were computed, one based
on,the number of variables
(questionnaire items) keyed and the other based on the nktmber of individual
characters keyed (one or more per variable).
For example
/\
"040"_ hours would
be considered ope variable consisting of the three characters:
"0," "4," and
"0."
A total of 922 sets of triplicate questionnaires were sampled.
The
t.riplicate records were compared variable-by-variable and
character-by-character
(excluding open-ended questionnaire items) by a computer Program which identi-
.
4
fied the variables (questionnaire items) and characters (within variables)
that were not keyed in exactly the same manner.
As indicated above, the master
keying of a variable or charatter was.considered correct if matched by at
least one of the two rekeys.
SimDle counts of the number of rekeyed variables
and characters for which neither rekey matchbd the initial keying were computed,
and these counts were converted to error rates by dividing by the number of
keyed variables and the number cs
keyed characters, respectively.
'The resulting
overall, variable and character error rates for individual direct data entry
operators are presented in Table 1.
From-the start of fourth follow-up.data entry operations,
/
computer
reports were 'generated at various points in the procesa to indicate the overall
variable and character data entry error rates.
A computer listing of the
variable (questionnaire item) errors that*were detected in each report was
produced simultaneously.
During initial data entry activity, reports generally
were produced on a weekly,basis and later on a biweekly basis as the
number of
questionnaires received at RTI decreased.
However, the frequency of these
quality control reports varied, depending on such factors as the number of
4/
As new operators were trained for NIS data entry, printouts of at least six
test questionnaires keyed by the new operators were manually compared with the
respective hard copy instruments by NIS project staff.
The new operators were
given additional instruction/retraining as necessary before beginning produc-
tion keying.
5