Presentation for Pew Research Center's Methodological Workshop on Public Opinion Research in Sub-Saharan Africa

1. Touchscreen
Data Entry
Errors
Dale Rhoda
Biostat Global Consulting
Pew Research Center
November 30, 2017

2. Touchscreen CAPI
data capture is
terrific for many
reasons

3. But of course
there are some
data entry
errors…

4. We don’t have
great data on
entry error rates;
they probably
vary by:
• Interviewer
• Question type
• Screen size
• Interface
• Protocol

5. N ≈ 550 dates per participant
Red rates include lazy entries
Blue rates count only good
faith efforts
Example: Entry Error Rates By Person

6. Paper capture &
keyboard
double-entry with
computerized
concordance
check yields
errors < 1%
Sometimes
described using
the Japanese
term:
poka-yoke

7. Touchscreen Error Rates Can Be Much Higher Than 1%
= Single-entry
= Double-entry
N = 10,830 dates

8. I am working
with the
developers of
Open Data Kit
(ODK) to test
changes to date
interfaces

9. I’d be happy to share
ideas on how to design
experiments to estimate
error rates in your context

10. Idea 1:
Develop kit with
different question
types -> generate
printed artifacts or
audio recordings -
> have prospective
hires enter
hundreds of items
-> use enclosed
spreadsheet to
estimate rates

11. Idea #2:
Share
anonymized
datasets that
include target &
entered items –
useful for
so-what
simulations

12. So-What Simulations
Generate
Clean Faux
Dataset
Analyze
Analyze
Contaminate Dataset
with Realistic Errors
(Many Times)
Evaluate
Consequences
of Entry Errors

13. Dale.Rhoda@biostatglobal.com