United States 

Department of

Agriculture

National

Agricultural

Statistics

Service

Research and

Development Division

Washington DC 20250

RDD Research Report

Number RDD-10-06

November 2010

Technology Advancing Data 

Collection: Thin Client 

Computer Assisted Personal

Interviewing in the National 

Agricultural Statistics Service’s

2010 Field Data Collection

Program

Michael W. Gerling

James M. Harris

This paper was prepared for limited distribution to the research community outside the United States 

Department of Agriculture. The views expressed herein are not necessarily those of the National 

Agricultural Statistics Service or of the United States Department of Agriculture. 

i

EXECUTIVE SUMMARY

The National Agricultural Statistics Service’s (NASS) primary purpose is to provide timely, 

accurate and useful statistics on United States and Puerto Rico agriculture. NASS conducts over 

400 surveys annually to estimate crop production, livestock, production practices, farm 

economics, etc. NASS has 45 field offices across the United States and one in Puerto Rico that 

are responsible for collecting agricultural data. These field offices employ various data 

collection methods: personal interview using a paper questionnaire, mail, telephone, and also 

Computer Assisted Telephone Interviewing and self-administered web.

Computer Assisted Personal Interviewing (CAPI) involves an interviewer going to the 

respondent with the questionnaire residing on a computer (generally a laptop) and recording all 

responses onto the computer. This data collection method is successfully being utilized by a 

number of organizations (e.g., the Natural Resources Conservation Service, the Census Bureau, 

Research Triangle Institute International, the Federal Emergency Management Agency, and the 

National Opinion Research Center). Improved timeliness of the data, reduced data entry costs,

and improved data quality are several benefits experienced by those implementing CAPI. 

However, all of these organization’s CAPI solutions involve storing data on the device and 

uploading it later in the day. The primary flaw with this solution is that it lends itself to the 

possibility (although remote) of data being compromised if the device is lost or stolen.

In the spring of 2009, Michael Gerling, Mark Harris, and Beth Edwards of NASS designed an 

innovative, thin client CAPI solution by leveraging wireless broadband technology and a 

recently completed web based data collection system. Hence, the name thin client CAPI was

coined. In general, a field interviewer accesses the Internet using a low cost netbook with a 

wireless broadband aircard. The interviewer accesses NASS’ data collection website and brings 

up the questionnaires that need to be completed by that particular agricultural operator. The 

interview is conducted real time over the Internet with no data ever residing on the netbook. To 

date, this innovative approach to CAPI, while evolving, continues to be successful.

1

Technology Advancing Data Collection: 

Thin Client Computer Assisted Personal Interviewing in the National 

Agricultural Statistics Service’s 2010 Field Data Collection Program

Michael W. Gerling and James M. Harris1

Abstract

The National Agricultural Statistics Service (NASS) surveys farmers and ranchers 

across the United States and Puerto Rico in order to estimate crop production and

number of livestock, to assess production practices, and to identify economic 

trends.

Computer Assisted Personal Interviewing (CAPI) involves an interviewer going 

to the respondent with the questionnaire displayed on a computer (generally a 

laptop). All responses are captured on the computer. Although CAPI has been 

around since the 1980’s, all previous forms of CAPI have centered around both 

the data and the data collection instrument being stored on the device. Also, over 

the past three years, there have been several accounts of agencies and businesses 

losing or having laptops stolen containing clients’ personal information. 

Although the possibility of someone bypassing the security mechanisms of the 

device and decrypting the data is small, it still exists. This possibility of data 

being compromised combined with the sensationalism of the news media can 

cause the general public to question the advisability of participating in surveys,

adversely affecting the entire survey industry.

NASS’ CAPI solution, coined thin client CAPI, is an innovative thin client 

approach which leverages wireless broadband technology and a recently 

completed web-based data collection system called Electronic Data Reporting 

(EDR). 

In general, a field interviewer using a low-cost netbook accesses the Internet 

using a wireless aircard. The field interviewer accesses NASS’ data collection 

website and brings up the questionnaires that need to be completed by that 

particular agricultural operation. The interview is completed real-time over the 

Internet with no data ever residing on the netbook.

Key Words: Agriculture, CAPI, Data Collection, Wireless Broadband, Aircards 

___________________ 

1/ Michael W. Gerling, Mathematical Statistician, of the National Agricultural Statistics Service’s 

Research and Development Division (NASS/RDD) and James M. Harris, Director of 

NASS/RDD, located at 3251 Old Lee Highway, Fairfax, VA 22030. Special thanks to Beth 

Edwards, also of NASS/RDD, for solving the technical issues to keep thin client CAPI both 

simple to implement and cost effective.
2

1.0 BACKGROUND

The National Agricultural Statistics 

Service’s (NASS) primary purpose is to 

provide timely, accurate and useful statistics 

on United States and Puerto Rico 

agriculture. NASS conducts over 400 

surveys annually to estimate crop and 

livestock production, production practices, 

farm economics, etc.

NASS has 45 field offices across the United 

States and one in Puerto Rico that are 

responsible for collecting agricultural data. 

These field offices employ various data 

collection methods: mail, telephone, and

personal interviewing using a paper 

questionnaire; Computer Assisted 

Telephone Interviewing (CATI) and selfadministered web.

In the 1980’s, Computer Assisted Personal 

Interviewing (CAPI) was tested and 

implemented in Indiana and Pennsylvania

(Eklund, 1991 and Pordugal, 1995). 

However, due to the high initial start-up 

costs of the hardware (laptops), short battery 

life, and difficulty in updating the survey 

instruments, this mode of data collection 

was discontinued. Meanwhile, other 

government agencies, institutions, and 

private companies continued to pursue CAPI 

and have incorporated CAPI into their data 

collection programs. The Natural Resources 

Conservation Service, the Census Bureau, 

the National Opinion Research Center, and 

the Research Triangle Institute International 

are all successfully using laptops, tablet PCs,

and personal digital assistants (PDAs) to 

collect data. Overall, they are experiencing 

improved timeliness of the data, improved 

data quality, and reduced data entry costs

(Gerling, 2004).

In 2003, NASS’ North Carolina Field Office 

pioneered NASS’ use of PDAs in data 

collection. They used PDAs to collect 

people’s opinions on North Carolina’s State 

Fair, in addition to Cotton Objective Yield 

Survey data (Neas, Molina, Hardegree, 

Gerling, 2006). Also, in 2003, NASS 

developed two new systems: Question 

Repository System (QRS) and Electronic 

Data Reporting System (EDR). 

Questionnaire design staff use the QRS to 

build paper questionnaires. EDR utilizes the 

QRS coding to create a self-administered 

web questionnaire. The web based 

questionnaires are rendered on the Internet 

for agricultural operators to complete online.

Since NASS’ first exploration into CAPI, 

hardware costs (laptops, PDAs and tablet 

PCs) have decreased while performance and 

functionality have dramatically improved. 

Laptops that once cost over $1,500 can now 

be purchased for around $300. In 2007, the 

introduction of low-cost netbooks also 

forced the prices of these devices even 

lower. This made the timing right for NASS 

to re-examine CAPI in 2009. 

2.0 CURRENT DATA 

COLLECTION PROBLEMS

Currently, NASS’ field data collection costs 

continue to rise. Postage costs for both the 

regular and express mailing of paper 

questionnaires between field offices and 

field interviewers are increasing. Personal 

delivery of completed questionnaires to the 

field offices, although timely, is not 

optimally cost effective, due to the time 

involved and mileage costs. 

Another issue NASS faces is that field 

interviews which occur on the last couple of 

days of enumeration result in completed 

questionnaires that are sent or handdelivered to the field office, sometimes too
3

late to be edited correctly and keyed 

properly into NASS’ data collection system. 

To handle the significant increase of data 

entry needed at the end of the data collection 

period, temporary data entry staff are hired. 

This is a costly solution that negatively 

impacts field offices’ budgets.

Also, the number of “cell phone only” 

households is increasing, and this is causing 

the survey industry trouble since now people 

may answer the phone, but are in an unsafe 

environment (i.e. driving) while trying to 

answer questions. And secondly, a majority 

of cell phone plans have a finite number of 

minutes to use, and those with cell phones 

may not want to respond to a survey that is 

going to use up their monthly minutes

allotment. This is pressuring the survey 

industry to conduct more face-to-face 

interviews just to obtain data.

Finally, over the past five years, there has 

been a dramatic rise of private companies 

and government agencies reporting laptops 

containing customers’ data being stolen or 

lost. This creates bad publicity and results 

in investigations into what occurred and 

why. In some cases, staff members were

fired and companies had to pay for identity 

theft services for their customers whose data 

may have been compromised. Overall, this 

adversely affects the entire survey industry 

and government agencies since clients may 

now question the security of their data.

Therefore, NASS wanted a solution that 

protects the agricultural operators’ data, is 

inexpensive, provides for simple training of

field interviewers, and that leverages current 

NASS systems while solving the problems 

noted above.

3.0 PROPOSED SOLUTION (Thin 

Client CAPI)

After much research and discussion with

numerous vendors on netbooks, laptops,

tablet PCs, aircards and wireless broadband 

technology, Michael Gerling, Beth Edwards 

and Mark Harris of NASS’ Research and 

Development Division developed an 

innovative new CAPI approach. The

solution was to use low-cost netbooks 

equipped with aircards to access and 

leverage NASS’ EDR data collection 

website to collect the data in real time. 

Thus, no data would ever be stored on the 

device, mitigating any concerns of the data 

being stolen or compromised.

This solution was coined thin client CAPI

(CAPITC), and it addresses and mitigates all 

of the problems discussed in Section 2.0. 

However, the plan for large-scale 

implementation is not yet feasible since 

wireless broadband coverage is not entirely

available across the United States and some 

surveys are not available on the EDR 

website.

Hence, the agency proposed a staggered

implementation to occur over several years 

across a handful of states each year. The 

initial states selected would be based 

primarily on the availability of wireless 

broadband coverage. The surveys chosen 

would be from those already available in

EDR.

These selected states would distribute the 

netbooks to field interviewers based on their

anticipated workloads and computer skills. 

Approximately ten field interviewers per 

selected field office would be provided with 

a netbook having wireless broadband access. 

The number of devices allocated per field 

office was capped at ten, due to budgetary 
4

constraints. As the implementation budget 

increases, more field interviewers would be 

provided the necessary hardware and 

training to conduct interviews via CAPITC. 

Training would be a mixture of classroom, 

field, and video on how to use the netbooks

and navigate EDR surveys. Afterwards,

field interviewers would be ready for 

CAPITC enumeration. 

3.1 CAPITC Interview 

A typical CAPITC interview would start with

the field interviewer arriving at the 

agricultural operation of interest and

obtaining the operator’s permission for the

interview. The field interviewer would log

into the netbook, connect to the EDR

website, and obtain the questionnaires for 

the operation. Next, the field interviewer

would conduct the interview over EDR via 

wireless broadband access. Data security is 

maintained since EDR is password protected 

and employs Secure Socket Layer 128 bit 

encryption. The wireless broadband signal 

is also encrypted.

After completing the interview and 

submitting the reported data, the field 

interviewer would thank the respondent for 

his/her time, log out of EDR and the 

netbook, shut down the netbook, and return 

it to its case.

The collected data would reside on the EDR 

server, from which the data could be

processed by the field office for review, 

editing, and analysis. No data would ever be 

stored on the netbook. 

Finally, the field interviewer would return to 

his/her vehicle and plug the netbook into the 

provided car charger, so that it would be 

ready for the next interview. See Figure 1.

Figure 1:

USDA- NASS Field Office

Thin Client CAPI Illustrated

Agricultural Operation Field Interviewer

Cell Tower

EDR

Web Survey Site
7

The primary limitations of CAPITC and the 

proposed solutions are as follows:

Limitation -- Connectivity is established, but 

subsequently lost.

Solution -- All data collected on previous 

web pages would be saved. Data for the 

current web page and subsequent pages 

would then be collected via paper. Later on, 

when connectivity is re-established, the field 

interviewer would enter the data from the 

paper questionnaire into the EDR system.

Limitation -- Connectivity is unavailable at 

the time of the interview, or the 

environment/weather makes conducting a 

CAPITC interview impractical.

Solution -- Data would be collected on the 

paper questionnaire and later entered into 

the EDR system.

3.2 Expected Benefits

Computer Assisted Personal Interviewing

has the following benefits:

 it minimizes paper questionnaires

(including storage and eventual 

shredding costs),

 it reduces the amount of data entry 

from the office,

 it provides the ability for 

supervisors to review work right 

after the interview is conducted,

 it improves data quality by using 

real-time edit checks, and

 it reduces mailing costs in 

shipping 

materials between the office and 

the field interviewers.

Thin client CAPI has all of these benefits 

with the added perks of doing this more cost 

effectively and eliminating the risk of a 

respondent’s data being compromised.

4.0 IMPLEMENTATION

Even good change has resistance and 

CAPITC was no exception. The paradigm of 

having the questionnaire and data on the 

device and, at night, uploading and 

downloading information had been around 

for years and it was “How everyone else was 

doing it.”

 

However, through additional research and 

testing, CAPITC is now viewed as a vital part 

of moving NASS forward to meet the everchanging agricultural industry.

To implement CAPITC, a team composed 

primarily of staff from NASS’ Census and 

Survey Division, responsible for the 

operational workings of CAPITC, was 

formed.

4.1 Equipment

The netbook selected for initial 

implementation was the Lenovo S10e,

priced at $300. It was purchased with an 

extended battery which provides

approximately six hours of use. The screen 

is visible indoors and outside. This model

also comes with an express slot for the 

aircard. The express aircard format was 

selected over the typical USB aircard since 

the express type lessens the likelihood of the

field interviewer losing the aircard, while 

minimizing any damage to the aircard if a

netbook was dropped or bumped. 

Aircards were from three wireless

broadband carriers (AT&T, Sprint and 

Verizon). The aircards themselves were 

free, but a monthly service fee of 

approximately $40 was incurred per card.
7

Finally, an inexpensive netbook case ($20) 

and a car charger for netbooks ($9) were 

purchased.

4.2 Where to Implement?

After reviewing aircard coverage maps, and 

conducting tests of the aircards, the team 

decided to implement CAPITC in New Jersey 

and Indiana.

One aircard was distributed per field 

interviewer based on the overlap of their 

assigned data collection territories with the 

broadband coverage maps from each of the 

carriers. There were some instances of field 

interviewers receiving aircards from more 

than one carrier in order to determine which 

carrier would provide the greatest 

connectivity. Although having multiple 

carriers’ aircards would be ideal, NASS 

found that providing each field interviewer 

with only a single service provider’s aircard 

was more cost effective.

5.0 INITIAL FINDINGS

In general, NASS’ field interviewers consist

primarily of retirees with varying levels of 

computer skills. For the initial 

implementation, those field interviewers

having the best computer skills were 

selected. This would not only help in 

ensuring a good start but also enable these 

first CAPITC interviewers to be future 

trainers for those not initially receiving the 

training. 

Instruction consisted of a half day in the 

field office educating office staff on CAPI

TC

and addressing any concerns. The second 

day focused on instructing the field 

interviewers on how to use their netbooks 

and aircards and how to access and navigate 

the EDR system. The instruction was 

classroom style with several opportunities 

for hands-on practice.

Overall, the field interviewers found using 

the netbooks and aircards rather 

straightforward. Most of the questions 

centered on the EDR system. Field 

interviewers had several questions on how 

survey questions were rendered on a web 

page and on the logistics of navigation 

between pages. Although the time 

discussing the on-line questionnaires greatly 

extended the training to a full 8 hours, the 

comments obtained will significantly 

improve EDR’s on-line instruments not only 

for CAPITC but also for the agricultural 

operators who access the on-line 

questionnaires through self-administration. 

As the field interviewers moved from the 

classroom to the real world, they found that 

some netbooks took over 15 minutes to boot 

up. The first solution was to have field 

interviewers always logged on to the 

netbooks. This circumvented the boot-up 

time, but with the netbooks always on, heat 

generated from the netbooks would literally 

fry the express type aircard, causing the 

ability to connect or hold a steady wireless 

broadband connection uncertain. The 

second solution was to remove all of the 

unneeded software that came on the 

netbooks. This resulted in an overall boot 

up time of 3 to 5 minutes which was a 

substantial improvement.

Overhead power lines and buildings with 

thick (especially metal) walls would also 

negatively affect the ability to connect or 

hold a broadband signal. This problem, 

however, appears to be mitigated by using 

Sprint’s Overdrive or Verizon’s Mi-Fi. 

These standalone devices are smaller than a 

deck of cards and contain a built in aircard

and battery. Once the device connects, the 
7

device creates a Wi-Fi hot-spot which seems 

better at penetrating walls. The netbook 

obtains the Wi-Fi signal to access the 

Internet and EDR. Additional testing still 

needs to be conducted, but preliminary 

testing supports the effectiveness of this 

approach.

6.0 LESSONS LEARNED

As with implementing any new technology, 

there is a learning curve. However, the 

simplicity of CAPITC was the saving grace 

of the initiative. For those looking to adopt 

CAPITC into their business, the following 

sections of this report contain some of the 

lessons learned when adopting this data 

collection method.

6.1 Equipment

Price isn’t everything. Depending on the 

location and type of data being collected, 

netbooks are not necessarily the best 

solution. Paying a little more for a low cost 

convertible or tablet PC may shorten the 

interview and save more money over the life 

of the device. When a low cost convertible 

tablet PC was purchased and tested with 

field interviewers, all of the interviewers

preferred using the tablet PC’s stylus over

the netbook’s touch pad.

All devices (laptops, netbooks, tablet PC’s, 

aircards, etc...) need to be configured 

correctly ahead of time. Attempting to do 

this at the training site wastes valuable time,

and it’s extremely difficult to make sure all 

equipment is configured correctly. All 

unneeded software needs to be removed 

during the configuration process. This will 

significantly shorten the boot up time.

Keep it simple. The fewer mouse clicks/key 

strokes for field interviewers to press or 

select on the device, the better. One shortcut 

that can be implemented is having the 

aircard automatically connect to the Internet 

after logging in.

6.2 Training

Recommend that training be a combination 

of classroom, hands-on and outdoor training. 

Make sure that the training room has

wireless broadband capability. 

7.0 CAPITC or CAPI?

Currently, NASS’ implementation of 

CAPITC is still in its beginning stages. As 

compared to other agencies’ CAPI solutions, 

NASS’ CAPITC approach appears to be 

more cost effective and requires less start-up 

cost.

CAPITC can use low cost netbooks while 

regular CAPI requires a more expensive 

laptop due to the added security measures 

needed for storing and transferring data. 

CAPITC requires less technical support since 

there is less software required to maintain

and all of the data transfer is done real-time 

over the Internet. In contrast, CAPI requires 

additional data transfer and security 

software solutions which can conflict with 

one another. Typically, the technical staff 

required for standard CAPI tech support 

would be more than twice the size of the one 

needed for CAPITC technical support. (See 

Gerling 2004.)

CAPITC only requires one full day of 

training, whereas standard CAPI training is 

typically conducted over several days. This 

additional training is due to the time it takes 

to instruct on how to upload and download 

data, as well as how to log in through all of 

the security protocols.
8

Standard CAPI, however, does shine in its 

ability to conduct an interview regardless of 

wireless broadband coverage. Although 

wireless broadband coverage is expanding, 

the ability to conduct an interview via a 

computer at any location is currently a major 

plus for CAPI. 

Focusing on data security and the public’s 

concern with identity theft, standard CAPI is 

more vulnerable to data being compromised. 

This risk is due to collected data being

stored on the device at various times during

the data collection period. Eventually, a 

CAPI netbook, tablet PC, or laptop will be 

lost or stolen. Although the device is 

password protected and the data are

encrypted, there is still a chance (although 

minute) that the data could be compromised. 

If NASS were to implement CAPI and a 

device containing agricultural operations’ 

data were stolen or lost, the problem would 

be how this would affect the agricultural 

industry’s and the general public’s 

perception of NASS. Another potential 

problem is the impact of any media 

coverage on a lost or stolen NASS CAPI 

device. This could become a public 

relations problem for NASS and the survey 

industry. The Census Bureau, Internal 

Revenue Service, General Electric 

Corporation and Wells Fargo have all had 

laptops containing clients’ data lost or 

stolen, which has resulted in negative media 

coverage and employees being either 

released or demoted. Also, in the case of 

Wells Fargo, the company had to pay for a 

year’s worth of identity theft services for 

those clients whose data may have been 

compromised.

By contrast, CAPITC data are never stored 

on the device, so a loss would strictly be a 

financial one, not a data security one. Also, 

NASS could take a loss and turn it around to 

promote its data collection efforts and 

explain why the agency chose the CAPITC

solution so as to protect the farmers’ data. 

Overall, as wireless broadband continues to 

expand, the CAPITC solution will become 

more and more cost effective. 

8.0 FUTURE

Technology is continuing to evolve, and 

wireless broadband continues to cover more 

rural areas. The American Recovery and 

Reinvestment Act of 2009 has also created 

over 120 projects to significantly enhance 

broadband and wireless broadband access in 

rural areas. Urban areas are also seeing

increases in data transmission speed with the 

introduction of 4G wireless broadband. 

Also, technology that combines both aircard 

and satellite technologies is making its way 

to market.

 

In April of 2010, Apple Corporation made a 

major move into the tablet industry with the 

introduction of the iPAD at an aggressive 

price point of $500. Also, Apple 

Corporation’s pricing of its wireless 

broadband service starting at $15 is placing 

pressure on all wireless broadband carriers 

to lower their prices as well. In early April, 

NASS was able to procure an iPAD and 

soon realized that this device has much 

promise. The iPAD is currently NASS’

device of choice for CAPITC

implementation.

CAPITC has also opened future 

opportunities. Over the next 3-5 years, this 

data collection method has the potential to 

provide directly/indirectly the following

capabilities:
9

a. Enable field staff to complete 

timesheets and expense reports 

on-line.

b. Provide access to interviewer 

manuals on-line.

c. Improve data quality (via edit 

checks).

d. Provide real time routing and 

navigation for field interviewers 

driving to agricultural operations.

Over the next ten years, NASS’ CAPITC

could morph into CAITC (CAI = Computer 

Assisted Interviewing). In CAITC, the field 

interviewers would conduct both personal 

and telephone interviews using the EDR 

questionnaires as computer assisted 

telephone interview instruments. This will 

cause additional paradigms of staffing needs 

and data collection to be re-thought. Note: 

At the time of writing, CfMC (a company 

based in San Francisco, CA) is now offering 

their research services for broadband CAPI 

and WebCATI solutions. Hence, this 

paradigm shift has already begun.

Thin client CAPI’s simple model provides 

flexibility to adapt to NASS’ ever-evolving 

business needs, to meet current and future 

demands of the agricultural industry and 

those of the federal government. 

9.0 REFERENCES

Gerling, M. (2004) “A New Look Into 

Portable Electronic Devices for Field Data 

Collection in the National Agricultural 

Statistics Service”, (White Paper) United 

States Department of Agriculture, 

National Agricultural Statistics Service.

Neas, K., Molina, J., Hardegree, J., Gerling, 

M. (2006) “Using Personal Digital 

Assistants for the 2004 Cotton Objective 

Yield Survey”, Research and Development 

Report RDD-06-01, United States 

Department of Agriculture, National 

Agricultural Statistics Service.

Eklund, B. (1991) “Mobile Computerized 

Data Entry And Edit For The Livestock 

Prices Received Survey”, SRB-91-10, 

United States Department of 

Agriculture, National Agricultural Statistics 

Service.

Pordugal, T. (1995) “The Effects Of Editing 

And A Review Of Warning Errors From A 

CAPI/IE Perspective”, SRB-95-05, United 

States Department of Agriculture, 

National Agricultural Statistics Service.