Comments on three papers presented at FCSM meeting on 

November 15th, 2001 

Shoreh Elhami, GIS Director 

Delaware County Auditor 

The three papers presented at “Issues in Geospatial Data Collection” session at FCSM 

conference were of various natures and therefore, the following comments will address 

each one separately. 

1) Using Digital Geospatial Information to Locate Sample 

Units in the Field 

With todays increasing use of mobile devices in a variety of applications, determining the 

effectiveness of these equipments in the field has become a critical issue. This paper has 

investigated the efficiency of two types of mobile devices for locating hard to find outlets 

in an urban area. 

The paper discusses 3 stages of data collection (orientation, navigation, identification) 

using a handheld device loaded with a commercial mapping software, as well as a tablet 

PC also loaded with a commercial mapping software and connected to a GPS receiver. 

The study has concluded that using commercial mapping software along with a GPS will 

increase the efficiency of planning a route, navigating to addresses and identifying outlets 

specially when the staff is unfamiliar with the territory. Their team was comprised of 

staff with varying skill levels and from different age groups which assisted in identifying 

important issues such as: the role of having prior familiarity with computers/new 

technology, mapping software programs, and also the role that the age of the data 

collector may play. 

It was particularly determined that an easy to read interface, a larger display and larger 

fonts, as well as displaying minimal information would be crucial in increasing the 

efficiency of the process. Written directions and graphic display of the route played an 

important role and the interactivity of the mapping software provided for a flexible 

environment thru which the driver had a better chance of recovering from errors. In 

regards to the tablet pc and the GPS, it was determined that this setup increased the 

confidence level of the staff especially where they were unfamiliar with the area. 

While the study has successfully analyzed a variety of issues regarding the use of the 

mobile devices for determining locations of hard to find addresses, the following 

suggestions may further compliment this study: 

• Conduct identical tests (on the same outlets) in the same areas by people of 

similar demographic and expertise in a traditional fashion (using strictly paper 

maps) and compare the results and productivity rates with when the handheld 
device was used alone and when the tablet pc and GPS receiver was utilized. It 

would especially be interesting to find out if the mapping software would be as 

useful at the planning and navigation stage if the staff is familiar with the area. 

Experiment the process with the following variations: 

• In areas with varying address types (rural addresses, multi-use units) 

• In fast growing areas (containing many new streets) with commercial street 

databases and more accurate local datasets 

• In areas containing inaccurate/misaligned road network (from the geometric 

standpoint); especially find out how useful the GPS is in these areas 

• With devices equipped with audio instructions 

• By comparing the affects of providing audio instructions vs. sending one or two 

individuals to the field 

• By testing other map software programs, especially those that may combine the 

GPS and mapping application in the same package 

• With adding imagery to the dataset (on the tablet pc) and analyzing its impact on 

identification stage 

• By adding an application that provides for automated routing and even reporting 

live traffic information 

• By using a dual display system (one to display directions and the other, the map 

and the best route), both installed in the vehicle 

• By testing the process in areas containing detailed supporting data (point 

coverage, parcel data, landmarks) and study its impact on the orientation and 

navigation stages 

• By using the GPS unit for identifying individual addresses in multi-unit 

residential or commercial uses 

• Add data entry stage to the existing 3 stages and experiment with other software 

programs that accommodate that task. Test the process: 

• With GPS receivers of various accuracy levels 

• By applying differential Correction (either real-time or post correction), 

and further research the skills and training required for this task 
2) Geospatial Data Collection and Analysis as Crucial Process 

in an Integrated Census 

This paper proposes an ambitious plan for Israel’s 2006 Census. It is evident that the use 

of GIS as an integral part of the entire process will provide for boundless opportunities, 

however, the success of this project will heavily depend upon several key elements. 

The first and most important element is having a comprehensive and high quality dataset. 

A high quality dataset means: accurate, current, and well-documented datasets, either in 

spatial or non-spatial formats. 

Some base spatial data layers very important for this process can be listed as: 

• A road centerline (populated with current and accurate address ranges to allow for 

effective geo-coding) 

• A point coverage of units including their xy coordinates and other unique 

identifiers (such as a unique parcel number, address, and etc. so it can be used as a 

relate/link item) 

• Other supporting data layers at a more detailed scale such as cadastral/property 

ownership layers whenever they are available 

There can be a variety of administrative datasets such as: 

• Utilities 

• Voter registration 

• Welfare recipients 

• Population registration 

• And etc. 

The Israeli’s spatial database includes a comprehensive GIS dataset including a point 

coverage of all structures within the country. The point coverage in particular will play an 

integral role in the success of their project. Israel’s nationwide cadastral coverage and 

their accurate street database are only complimentary to this rich dataset. 

The second important element is establishing a level of confidence (which is mentioned 

in this paper as a Reliability Index) in every dataset used in the process. Close 

examination of every datasets’ Metadata is an absolute necessity. When examining the 

Metadata, each datasets’ currency, accuracy level, geographic extent, any embedded 
standards, contact points, and most importantly any potential spatial items must be 

identified. 

Thirdly, it is very critical to select administrative files appropriate for targeted areas or 

purposes. This could provide for more focused and efficient results mainly due to dealing 

with a smaller geography. 

For example, in fast growing areas and also areas with a large number of multi-use units, 

the voter registration file may be the most suitable file to determine the locations of 

residents in an area. The addresses of these units are often missed if only cadastral 

datasets are used. 

The fourth element deals with increasing the number of administrative files. Using a large 

number of administrative files and linking them can become very tricky and can create 

extremely complex scenarios. Additionally, lack of standardization (specially for 

addresses) could become a great hindrance in the process. 

The success resulting from the last element may become the most challenging one since it 

requires collaboration and reaching agreements among various governmental and at times 

non-governmental entities. 

Israel’s innovative approach is impressive and detailed results of the country’s 2006 

Census including: data gathering and creation, creating linkages between various 

datasets, and effectiveness of GIS technology should be carefully examined. 

3) Evaluating the Use of Residential Mailing Addresses in a 

Metropolitan Household Survey 

The conclusion of this paper indicates that using residential mailing addresses and 

specifically, the correlation between the results of the Half Open Interval procedure and 

actual missing addresses for developing a metropolitan survey are beneficial in 

comparison to traditional methods. 

The project is conducted in Dallas County, Texas and on a database containing 818,000 

mailing addresses. It is worth to mention that the quality of the Delivery Sequence File 

and the road centerline utilized for this project, especially in a large and densely 

populated area such as this, is quite unique and exceptional. Achieving 99.4% hit rate is 

quite impressive and very difficult to achieve in many other areas of the country 

particularly in areas with rural addresses or fast growing regions. 

Therefore, entities utilizing this method must first examine the currency, and 

completeness of DSF. DSF files in other parts of the country may not be as complete as 

Dallas County’s database and that can adversely impact the effectiveness of the HOI 

methodology. 
Another important issue to consider is to closely examining the quality of the road 

centerline used for geo-coding. Even enhanced TIGER-based road centerlines include 

missing roads and in some cases even though the roads exist, the address ranges are 

absent or incorrect which could result in low hit rates when geo-coding the files. 

Utilizing HOI in conjunction with DSF is a natural match and GIS is a perfect tool for 

identifying and displaying locations of missing addresses in a sequence. However, the 

delivery sequence must be closely examined for unusual patterns. 

Finally, it is worth to mention that HOI procedure could be effectively used for periodical 

Quality Control of any entity’s DSF and for comparing the results with localities’ Master 

Address Files for achieving a more complete coverage. 

Literature Cited: 

Nusser, S. M. and Fox, J. (2001). Using Digital Geospatial Information to Locate Sample 

Units in the Field, 2001 FCSM Paper. 

Blum, O. and Calvo, R. (2001). Geospatial Data Collection and Analysis as Crucial 

Process in an Integrated Census, 2001 FCSM Paper. 

Iannacchione, V. G. and Staab, J. and Redden, D. (2001). Evaluating the Use of 

Residential Mailing Addresses in a Metropolitan Household Survey, 2001 FCSM Paper. 

Kish, L. (1965). Survey Sampling, John Wiley & Sons, New York.