THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering and Medicine
Committee on National Statistics
Division of Behavioral and Social Sciences and Education
The Keck Center 500 Fifth Street, NW Washington, DC 20001 Phone: 202 334 3096 Fax: 202 334 3751 www.national-academies.org/cnstat
May 18, 2010
Dr. Richard Newell
Administrator
U.S. Energy Information Administration
1000 Independence Avenue, SW Washington, DC 20585
Dear Dr. Newell:
At the request of the Energy Information Administration (EIA), the Committee on National Statistics (CNSTAT) of the National Research Council convened a panel to conduct a comprehensive 30-month study of the Commercial Buildings Energy Consumption Survey (CBECS) and Residential Energy Consumption Survey (RECS). Many of the design and operational procedures for the CBECS and RECS were developed in the 1970s and 1980s, and resource limitations during much of the time since then have prevented EIA from making significant changes to the survey methodology or operations. With the possibility of additional funding available in the next few years, EIA asked the National Research Council to conduct a comprehensive review to assess how the CBECS and RECS can take advantage of recent developments in survey methods and to ensure the relevance of the data for meeting increased user needs in the next decade and beyond. The panel’s charge is to consider possible improvements to data quality, geographic coverage, relevance, and the timeliness of data releases.
Because plans for the upcoming 2011 round of CBECS must be finalized in the near future, the panel was charged to comment as soon as possible on design and data collection options that would enable the upcoming round of this survey to better support U.S. Department of Energy program information needs, reduce respondent burden, and increase the quality and timeliness of the data. This letter responds to that request, and is limited in scope to discussing issues that the panel believes are realistic to consider in the timeframe leading up to the 2011 data collection. At the conclusion of the study, the panel will deliver its comprehensive report on the overall design and conduct of both CBECS and RECS.
At the first meeting of the panel on February 1-2, 2010, EIA staff discussed preparations for the 2011 CBECS and indicated that work will begin on the 2011 CBECS sample design in the summer of 2010. Thus, any changes to this round of the data collection would have to be evaluated before then. EIA staff also informed the panel that the 2011 CBECS is anticipated to have more funding than it has had in the past. The panel also learned in those discussions that EIA has relatively little empirical data on how well the current design and procedures are
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Committee on National Statistics The Keck Center
Division of Behavioral and Social Sciences and Education 500 Fifth Street, NW
Washington, DC 20001
Phone: 202 334 3096
Fax: 202 334 3751
www.national-academies.org/cnstat
May 18, 2010
Dr. Richard Newell
Administrator
U.S. Energy Information Administration
1000 Independence Avenue, SW
Washington, DC 20585
Dear Dr. Newell:
At the request of the Energy Information Administration (EIA), the Committee on National
Statistics (CNSTAT) of the National Research Council convened a panel to conduct a
comprehensive 30-month study of the Commercial Buildings Energy Consumption Survey
(CBECS) and Residential Energy Consumption Survey (RECS). Many of the design and
operational procedures for the CBECS and RECS were developed in the 1970s and 1980s, and
resource limitations during much of the time since then have prevented EIA from making
significant changes to the survey methodology or operations. With the possibility of additional
funding available in the next few years, EIA asked the National Research Council to conduct a
comprehensive review to assess how the CBECS and RECS can take advantage of recent
developments in survey methods and to ensure the relevance of the data for meeting increased
user needs in the next decade and beyond. The panel’s charge is to consider possible
improvements to data quality, geographic coverage, relevance, and the timeliness of data
releases.
Because plans for the upcoming 2011 round of CBECS must be finalized in the near future, the
panel was charged to comment as soon as possible on design and data collection options that
would enable the upcoming round of this survey to better support U.S. Department of Energy
program information needs, reduce respondent burden, and increase the quality and timeliness of
the data. This letter responds to that request, and is limited in scope to discussing issues that the
panel believes are realistic to consider in the timeframe leading up to the 2011 data collection. At
the conclusion of the study, the panel will deliver its comprehensive report on the overall design
and conduct of both CBECS and RECS.
At the first meeting of the panel on February 1-2, 2010, EIA staff discussed preparations for the
2011 CBECS and indicated that work will begin on the 2011 CBECS sample design in the
summer of 2010. Thus, any changes to this round of the data collection would have to be
evaluated before then. EIA staff also informed the panel that the 2011 CBECS is anticipated to
have more funding than it has had in the past. The panel also learned in those discussions that
EIA has relatively little empirical data on how well the current design and procedures are
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working in comparison with approaches that have been tried in the past and that EIA has not
conducted an analysis of options considered but not pursued. Based on the factors described
above, the panel’s overarching recommendation is to invest some of the currently available
additional funding in research that will enable EIA to make future decisions based on empirical
evidence about what is most likely to improve geographic coverage, data quality and relevance,
while controlling costs. The panel’s specific recommendations for research as part of the 2011
CBECS are described below.
BACKGROUND ON THE CBECS
The CBECS is a survey of commercial buildings in the United States, mandated by Congress to
provide comprehensive information about energy use in commercial buildings. In addition to
energy consumption and expenditure data, the survey collects information about building
characteristics, such as energy source, physical structure, equipment used, and activities
performed, which provides researchers with detailed information about commercial sector
energy use and how it relates to building characteristics. The CBECS is the only national source
of these data, and is used for energy forecasting, program development, and policy development.
The survey collects information from a sample of commercial buildings in the United States, and
it is administered in two data-collection stages: a Building Characteristics Survey and an Energy
Suppliers Survey. During the first stage of the data collection, interviewers visit the buildings
selected into the sample and ask a representative of the building, such as the building’s owner,
manager, or other knowledgeable person to complete the survey. During the second stage of the
data collection, the energy suppliers of buildings that were not able to provide adequate
information in the first stage are contacted to obtain actual usage and expenditure data from the
supplier’s records.
SAMPLING FRAME
There is little comprehensive information about the stock of commercial buildings in the United
States, and EIA indicated that the lack of a comprehensive national list of commercial buildings
or another suitable source from which to select a sample of buildings to interview is one of the
major challenges for the CBECS data collection. Because no complete list of buildings is
available to use as a sampling frame, EIA builds a new area probability sampling frame for the
CBECS on a decennial basis. The frame is based on field listings of commercial buildings within
specified geographic areas. This sampling frame is updated between each data collection.
However, field listings are resource intensive and relying on sources that are not comprehensive
for updating the sampling frame leads to coverage problems.
The CBECS sample design has undergone numerous revisions over the years, as EIA has
attempted to address the cost and coverage issues, but most rounds of the CBECS have relied on
a combination of an area frame and a list frame, based on existing lists of commercial buildings
from a variety of sources and added at the second stage of the area frame sample. The primary
sampling units have been counties or groups of counties, within which smaller geographic areas
were randomly selected. All commercial buildings were listed and stratified within these smaller
areas, and then a sample of buildings was randomly selected from each stratum. This approach
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was supplemented with information from existing building lists from other sources to ensure
adequate representation of buildings that were of special interest because of their size or type of
primary activity.
For the 2007 administration of the CBECS, the 2003 sampling frame had to be updated. At the
recommendation of the data collection contractor, the National Opinion Research Center
(NORC), the update was based on a U.S. Postal Service (USPS) Delivery Sequence File (DSF)
purchased from a vendor licensed by USPS. The DSF is USPS’s list of all delivery points in the
United States. Using the DSF for updating meant that this list had to be matched to the addresses
in the second-stage area frame and the duplicates removed. NORC reported that the
unduplication turned out to be a major challenge, in part because of imprecise address records.
As EIA is aware, another major redesign of the CBECS sampling frame could be very
productive, but due to the limited time and resources available, this is neither feasible nor
recommended for the 2011 data collection. However, leading up to and during the 2011 CBECS,
alternative approaches to building a good second-stage sampling frame should be the focus of
EIA research, particularly the availability of administrative records and lists. As the EIA staff
indicated, and the panel concurs, a sampling frame based on administrative records may have to
completely or partially replace the second-stage area frame in the future because of the high
costs associated with field listing. Although EIA has considered the use of more lists throughout
the years, research on this should continue because the availability of sources of data is
constantly evolving, particularly with more information becoming available on the Internet.
For the 2011 CBECS, the most practical approach is to perform another round of updating of the
sampling frame using the DSF. Even though unduplication proved to be a challenge when the
DSF was first used in 2007, presumably the bulk of the work has now been done, and the 2011
frame can be updated by simply matching the new addresses to the address files used in 2007.
We assume that a 2003-2007 cohort of listings is available for use in the 2011 sample based on
the matching and updating performed in preparation for the 2007 data collection. As was done in
previous years, this approach would have to be supplemented with lists from other sources to
assure adequate representation of buildings of special interest.
As an example of such a supplemental source, we recommend exploring the usefulness of local
government databases that are available online, such as county property tax databases, some of
which include information on square footage and heat source. Two available online databases of
which we are aware are those of the Allegheny County Office of Property Assessments in
Pennsylvania and of the King County Government in Washington. Although such databases are
not universally available online, and their use would undoubtedly present some standardization
challenges, their usefulness should be evaluated for two purposes: as a source for a sampling
frame and for the possible use of some of the data that are now collected through interviews.
Other possible data sources are discussed in the next section, although all require further research
to evaluate them.
In rural areas, the DSF often includes only rural route or post office box numbers and so tends
not to be very useful. EIA should evaluate information available from vendors who specialize in
providing address data to fill these types of gaps. If these sources are found to be inadequate,
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field listing may still be necessary. Alternatively, half-open interval updating could be
considered, if relisting is deemed too inefficient because of the scattered nature of rural areas.
This technique involves updating only new or missed units within a small geographic area (an
“interval” associated with an address in the sample). In areas where buildings are scattered in
unusual ways, half-open interval updating may be difficult to carry out accurately, but the
accuracy of the approach in this particular context could be evaluated as part of the 2011
CBECS. For example, in addition to performing half-open interval updating in the rural sample
segments, relisting could also be carried out in a subset of these segments to compare the
outcome of the two techniques in terms of the number of listings identified and the number that
would end up being added to the 2011 CBECS. The relisting could be performed by experienced
listers or supervisors to minimize the costs associated with training for these types of
assignments.
Further research is needed to understand the quality and future potential of the DSF. In addition
to evaluating the performance of the DSF in comparison with other sources for a sampling frame,
the panel recommends adding a question to the CBECS questionnaire to better understand the
extent to which there is overlap between street addresses and the addresses where the building
occupants receive their mail. For example, one challenge is that the DSF contains business-level
entries, rather than building-level entries. Furthermore, some businesses have their mail
delivered somewhere other than the street address (for example, to a post office box).
SUPPLEMENTARY DATA SOURCES
In addition to considering existing administrative records as an alternative source for a sampling
frame, the panel recommends evaluating these records as potential sources for substantive data
that could possibly replace an on-site interview at the building’s location or could provide
additional data for modeling or to conduct new analyses. Relying on data from other sources may
become more of a necessity as it becomes increasingly expensive to maintain high response
rates, even if an ideal sampling frame of commercial buildings were available. Although
gathering and combining data from a variety of administrative records can also be resource
intensive, the costs may go down as such data become more widely available, especially online.
Such other sources may also provide higher quality data. For example, EIA staff have expressed
concerns regarding the difficulties associated with collecting data about the technical topics
covered in the CBECS survey. Neither the typical interviewer nor the typical respondent is
particularly knowledgeable about many of the items in the questionnaire, and this raises the
question whether there are other sources that could provide better quality data.
Because the CBECS is currently the most comprehensive data available on the energy
consumption of commercial buildings in the United States, there is no “gold standard” against
which the quality of the survey or other potential data sources can be evaluated. However, a
variety of other sources exist and can provide at least partial data. Comparing the data from
several of these sources will help EIA begin to understand the relative advantages associated
with each and the optimal ways of combining information from different sources. Ultimately,
conducting in-person interviews for at least a subset of the sample may be necessary for
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validation purposes, if the research indicates that these interviews produce the highest quality
data.
In the rest of this section we discuss some additional sources of data that should be explored and
validated at this stage, even if none of them, by itself, represents a realistic replacement for the
building interviews. The panel is aware that EIA has considered the use of a variety of
administrative records over the years. This option should be revisited periodically as the costs
and data quality benefits associated with integrating these data sources evolve, and the 2011
CBECS presents an opportunity to carry out this research. Although different sources may be
available for different types of buildings, for the purposes of evaluating them the overlap should
be maximized to the extent possible. In other words, a subset of the buildings should be selected
for this research and, for these buildings, data should be gathered from all of the available data
sources being evaluated. The overlap will be particularly important with the building audits, as
discussed below.
Building Audits
We understand that EIA has considered involving professional energy auditors to collect
building data instead of relying on interviewers, but there has never been sufficient funding to
implement this approach (except in the form of a small study in the past that was not conducted
in conjunction with any of the CBECS data collections). We recommend testing the use of
auditors on a small scale in the 2011 CBECS to better understand the costs and to collect data
that can be used to assess the quality of other data sources. The data collected by the auditors
would also be useful for evaluating some of the current back-end procedures, such as data
editing, or the regression model used to identify outliers and to initiate a supplier follow-up
survey.
For a subset of the buildings we think it would be useful if the same data were collected by both
interviewers and auditors to allow the evaluation of the differences between these two in-person
data collection approaches, in addition to comparing them to information collected from other
data sources. Even if geographic representation cannot be achieved due to cost considerations, to
the extent possible the test should include buildings of different sizes and with different
characteristics. The data collection should be performed by professional energy auditors, who
would carry out their work around the same time as the other data collection efforts relevant to a
particular building, and without knowledge of any data already collected or available about the
buildings from other sources.
Online Research
The panel recommends selecting a small subset of the buildings in the 2011 CBECS sample and
investigating the information that can be obtained about them solely from the Internet. This
could be set up in the form of a pilot test involving a small number of buildings (for example, 10
large, 10 medium, and 10 small buildings). The results will provide EIA with a better
understanding of what types of data are available online in terms of both quality and extent. If
this research is scheduled before the beginning of the data collection, the insights gained could
be useful in fine-tuning the data collection instruments and sample design for the 2011 CBECS,
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but this type of research could be carried out at any time. Once the 2011 CBECS data are
available, examining the consistency between the information available from a variety of Internet
sources and the data collected through the current methods, as well as from building audits, will
provide valuable information about data quality.
LEED and Energy Star Certified Buildings
Data quality can also be assessed by taking advantage of the information that is publicly
available online about buildings that have received leadership in energy and environmental
design (LEED) or energy star certification. Comparing the data collected through the building
interviews about a subsample or all of the buildings that have such certification to the data
submitted as part of the certification process for the same buildings can also contribute to a better
understanding of possible data quality issues. Naturally, certified buildings are a specific subset
of the CBECS sample, and their characteristics are not representative of the entire population of
interest for the survey. However, examining any discrepancies in the data available about these
buildings can improve EIA’s overall sense of the quality of the data and also identify potential
areas of concern. The comparison could even be performed on data that have already been
collected through a previous round of CBECS to inform the 2011 design.
Data from Energy Suppliers
The CBECS includes an energy supplier survey for about half of the CBECS buildings in the
sample. The survey is initiated in cases where the energy usage and cost information cannot be
obtained through a building interview or if the data obtained through the building interview are
flagged as out of the expected range based on a regression model developed by EIA. To evaluate
the quality of the data obtained from the building interviews, as well as the regression model
used to identify out of range responses, the next round of the CBECS should include an energy
supplier follow-up for more than just the problem cases currently included. For example, the
2011 CBECS could collect supplier data for a random sample of cases that provided usage and
consumption data that were deemed valid during the building interview.
Given the increasing interest in time-of-use, hourly, and real-time energy use data, the panel
recommends collecting this type of information as well, where available. EIA could aim to
collect hourly data or time-of-use data (along with rates) from a random sample of the suppliers
contacted for a follow-up interview, all suppliers who are contacted for a follow-up interview, or
a random sample of the suppliers for buildings for which interviews were also conducted.
In addition, it is possible to specifically identify a few buildings with real-time metering and
explore the data available from this source. The goal, again, would be to start establishing a
framework for integrating this type of data into future surveys, understanding what type of
information can be collected, and fine-tuning the procedures for working with a variety of (often
reluctant) energy suppliers.
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Digital Photographs
EIA has considered the use of digital cameras in the past, and this idea should be revisited, at
least as a one-time research effort. A test could be accomplished by either providing a small
number of the 2011 CBECS interviewers with cameras or in a separate operation from the 2011
data collection, if the latter approach is deemed more cost-effective because of training and
operational considerations.
Photographs may provide valuable basic information about buildings. EIA’s definition of a
building does not always correspond to a respondent’s definition of a building, and it is often left
up to the interviewer to clarify the definition and come to an understanding with the respondent
about what is meant by a building for the purposes of the interview. In addition, EIA staff
indicated to the panel that the buildings of interest tend to use a wide range of specialized
equipment related to building activity, and respondents’ abilities to describe the equipment vary.
EIA should evaluate the extent to which the pictures of the buildings and critical equipment,
including nameplates, are useful in the data cleaning and editing process (for example, for
reconciling ambiguous or questionable entries) and whether their use could translate into cost
savings in comparison to the current procedures. EIA should also investigate the privacy and
confidentiality concerns and regulations that may be applicable to the potential use of cameras in
this context, even if the pictures are only used for data cleaning and editing.
Geocoding
EIA should examine the costs and benefits of supplementing the data available about each case
in the sample with the geographic coordinates of the building’s address. Geocodes could be
added to the sample in house or during the data collection process. The former approach would
probably be less precise, so capturing this information during the field work would be preferable
if the interviewers can be equipped with the necessary devices at a reasonable cost. Adding
geospatial information to each of the cases in the sample will enable researchers to conduct
additional analyses of the CBECS data. For example, EIA currently integrates weather data from
the National Oceanic and Atmospheric Administration (NOAA) into some of its analyses, and
recording the building’s proximity to the closest weather station would expand the analytic
possibilities. Again, EIA should conduct research on any potential confidentiality concerns
related to the use of this type of data and whether there are ways of appending additional
geographic information to the data while maintaining confidentiality.
Other Data Sources
The panel recommends evaluating other existing data sources that EIA has considered in the
past, as well as the breadth and consistency of information that could be obtained from local
governments. The availability of more funding for the 2011 CBECS than has been available in
the past provides a unique opportunity to carry out research that can inform future decisions
about the design of the survey. Even if the information available from the various data sources is
limited in scope, the recommended research can provide valuable feedback about the quality of
the self-reported building data and identify options for integrating a variety of data sources in the
future.
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DATA COLLECTION
Process
The panel understands that EIA staff participate in all interviewer training, but even more active
involvement may be necessary to share the study’s goals and communicate how the quality of
the data determines their usefulness. In addition, EIA staff members are also best qualified to
conduct training on topics and concepts that are complicated, as a result of a long institutional
history, such as the definition of a building and of a qualified respondent.
Additional resources should be invested in analyzing the characteristics of the field operations
and in identifying opportunities for increased efficiency. EIA should review any information
available from the data collection contractor regarding the amount of time spent on cases of
various types (such as buildings with different characteristics, respondents with different
backgrounds, etc.). If the case level contact history is not recorded in sufficient detail, efforts
should be made to capture this information in the future. In addition, EIA should ask the data
collection contractor to schedule debriefings with the interviewers soon after the beginning of the
field period, and EIA staff should attend these debriefings to better understand how interviewers
spend their time in the field, what types of cases are presenting the biggest challenges, and why.
A detailed analysis of the time allocation should reveal whether there are subsets of cases that
require a disproportionately large amount of time to complete and whether the effort is justified
in the context of data needs and statistical techniques available to compensate for missing
information.
EIA should also work closely with the data collection contractor to review the procedures used to
select the best respondent for the building interviews and identify opportunities to streamline this
process. Again, debriefings with interviewers can provide invaluable feedback that can help fine-
tune the process and contribute to the development of new interviewer protocols. More efficient
procedures for identifying a qualified respondent can not only reduce costs, but also address
some of the concerns related to the technical nature of the questions. The qualitative feedback
from the interviewers can then be further examined with an analysis of the quantitative responses
by respondent type to identify possible differences in data quality. In other words, it is possible
that most of the questions are not “too technical” if posed to the right respondent.
Additional activities for which analyzing existing data could identify opportunities for increased
efficiency include the handling of partial interviews, both in terms of the field operations and
from the perspective of data editing. Given that the CBECS interview is relatively long (with an
estimate of 30 to 45 minutes provided to respondents), interviewer debriefings could reveal new
strategies for approaching buildings and asking for appointment times. It would also be useful to
understand whether there is a pattern to at what point the partial interviews end and whether the
order of the items in the questionnaire could be rearranged to make the partial interviews more
useful to EIA for either weighting or imputation.
Interviewers can be a good source of background and contextual information on questions that
are difficult to administer, especially on whether particular questions are leading to partial
interviews or possible data quality concerns. Discussions with the interviewers could represent
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the beginning of a close examination of the questionnaire that has evolved with a face-to-face
administration in mind and may need revising or simplifying to accommodate different future
modes of data collection, as described in the next section.
Modes
Although EIA has considered the use of other modes of data collection, CBECS data are still
collected primarily by in-person interviewing. In part because applying the CBECS definitions to
determine the boundaries of a building is not always a straightforward task, as discussed above,
EIA has continued to rely on face-to-face interviews. Identifying the most appropriate
respondent is another task that is thought to benefit from the presence of an interviewer.
Interviewers also carry hard-copy “show cards” that list the answer options for specific items and
can be handed to the respondent to assist with answering questions that may otherwise be too
difficult to remember if only read by an interviewer. In addition, one of the roles of the
interviewers is to scan utility bills if they are available.
To prevent declines in the response rates and to limit costs, EIA will have to revisit the use of
other modes of data collection, particularly the possibility of a multimode approach, with at least
a portion of the interviews being conducted online. Transitioning at least a subset of the
buildings to the web will free up some resources in the long run, which then can be allocated to
the more complex cases and possibly invested into increasing the sample size. Although
collecting this type of data on the web will present some methodological challenges, the panel
believes that these challenges can be addressed and that web data collection may also represent
some methodological advantages, in addition to the likely cost savings.
One possible approach that should be explored is to divide the sample into buildings that can be
relatively easily transitioned to a web administration and buildings with more complicated
characteristics that may benefit from interviewer administration. It may also be necessary to treat
large buildings differently from smaller ones. The review of the case histories and the
interviewer debriefings described above will be helpful in beginning to identify the building
types for which data collection is fairly straightforward.
Until reliable auxiliary data sources can be integrated into the data collection process, a first in-
person visit to each building will still be useful. During this visit, interviewers should follow a
protocol developed by EIA to determine whether a second in-person visit is necessary (as is
currently done) or whether the building is a good candidate for a web interview. Given the
concerns related to the definition of a building, the decision of whether a case can be transitioned
to the web will likely have to depend in part on whether the definition seems straightforward, as
it would be, for example, for a small, standalone building occupied by one business. Resources
should be invested in testing ways of communicating the definition of a building through a self-
administered format, in anticipation of possibly being able to transition more and more complex
buildings to web administration in the future.
The logistics of the best way to collect contact information for a web survey would have to be
explored. Possible options include obtaining the information during the first visit or by
telephone. Sometimes information on how to access a web survey is included in a hard-copy
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advance letter mailed to respondents, even though this is less ideal than an e-mail invitation
because it requires respondents to manually enter the web address of the survey and the login
information. Since contacting respondents by mail may be the only option if an e-mail address
cannot be obtained, investigating the extent to which building addresses and the mail delivery
addresses overlap (as recommended above) will also be useful for this purpose.
There is no question that identifying the best respondent for completing the interview is crucial
in the case of the CBECS, but exploring ways of accomplishing this without involving an
interviewer should be examined. It is possible that a web option could in fact contribute to more
interviews being conducted with qualified respondents. In some cases, it may be easier to
forward a questionnaire to the right person than to locate him or her in a building and arrange an
interview. In-person interviewers may also have an incentive to complete an interview as quickly
as possible by settling for a willing respondent rather than pursuing the most appropriate one.
If a questionnaire is available on the web, it is also easier for several respondents to collaborate,
each completing the sections he or she is most knowledgeable about. In addition, a web option
could result in more complete data because it gives respondents the option to obtain information
for questions they are not sure about and resume the survey later. Naturally, if respondents stop
or forward a survey, there is a risk that they will not return to complete it, so an extensive follow-
up effort is likely to be necessary. However, when a topic is too technical for many respondents,
such as is the case of the CBECS, this kind of follow-up could make a significant difference in
data quality.
The CBECS questionnaire relies very heavily on show cards, which is another reason why the
survey is administered face to face. However, the use of show cards raises the concern of order
effects, especially because many of the show cards have a large number of answer options listed,
making it difficult for respondents to focus equally on all of them. For example, the show card
listing the answer options for the primary activity in the building contains 16 items. A respondent
for a building with multiple activities may be tempted to select the first one that is applicable as
the “primary” activity instead of carefully reviewing the entire list. A web questionnaire would
make it easier to restructure these questions into layered sets of items, with fewer answer
options, or to reduce the possibility of primacy effects with the use of innovative methods, such
as the animated presentation of response choices or an eye-catching emphasis on the end of the
list.
The additional funding available for the 2011 CBECS represents an opportunity to test various
ways of asking questions that EIA has identified as problematic because of their technical nature.
For example, different approaches to obtaining the square footage information from respondents
can be tested in the form of a split-sample experiment. Deconstructing this kind of an item into a
series of questions would introduce complex skip patterns, but it would be easy to implement on
the web without increasing the cognitive burden on respondents. Web administration can
integrate various aids and tools for respondents, such as definitions or diagrams that can pop up
if a respondent seems to be having trouble with a question or requests help. The interviewer
debriefings described above will be useful in pinpointing specific questions that could benefit
from a different approach and whether web administration is a promising option to pursue.
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As is always the case with self-administered surveys, providing respondents with an e-mail
address and toll-free telephone number they can use if they have questions may be valuable. The
staff accessible through these means should be able to provide assistance related to the technical
topics in the questionnaire, as well as answer to questions specific to the web administration.
Finally, when evaluating the implications of transitioning to a mixed mode administration,
options for collecting the utility bills that are currently collected during the interview should also
be considered. Some respondents may be able to easily upload an electronic copy of their bills
through the questionnaire website, and this possibility should be investigated. Asking
respondents to mail a copy of their utility bills would probably not be cost-effective because
extensive follow-up would likely be necessary. The options should be assessed in the context of
the research conducted to evaluate the possibility of increased reliance on supplier data.
The ideal time for beginning to explore the feasibility of transitioning some of the sample to web
administration and conducting experiments on question wording is in parallel with the other data
validation efforts, especially the involvement of the energy auditors. This timing will allow EIA
to allocate some of the funding currently available to cover the cost of the transition, and it will
provide an opportunity to take maximum advantage of the data collected from different sources.
An analysis of the data collected from different sources can also guide decisions on whether the
in-person interviews can be used in the future to calibrate the data collected through the web. All
of the research should keep long-term plans in mind, such as the characteristics of the web as a
data collection mode, even if the integration of web interviews is not realistic for the 2011
CBECS.
DATA RELEASES
The panel learned that the schedule of the data releases is a major concern to users who would
like to see the lag between the data collection and release date reduced. EIA has been working on
taking greater advantage of the Internet to facilitate data distribution.1 We note that introducing a
web option during the data collection stage can, in the long run, reduce the time necessary for
preparing the files for release by reducing data editing and cleaning time.
The panel also recommends evaluating the possibility of eliminating some of the editing steps by
reducing the number of editing rules or the number of variables edited or by focusing on cases
that have the most impact on the estimation. Many data users will not only appreciate a shorter
lag between data collection and release, but may also prefer access to data with fewer edits.
SUMMARY
The 2011 CBECS presents an opportunity to conduct research that can guide the redesign of the
survey on the basis of empirical data about the most cost effective approach for collecting valid
and reliable information about the energy consumption of commercial buildings. This letter
1
Energy Information Administration. (2009). State Energy Data Needs Assessment.
Report SR-EMEU(2009)01. Washington, DC: U.S. Department of Energy.
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report of the panel outlines a variety of research topics that seem most promising to pursue
before or as part of the 2011 CBECS data collection. EIA should focus its efforts on (1)
evaluating the availability and quality of alternative data sources that could assist with sampling
frame development and potentially provide substantive data, and (2) developing a strategy for
transitioning some of the interviews to a web-based data collection mode. This research will
inform a possible future redesign of the sampling methodology and revisions to the data
collection procedures that could be considered for subsequent rounds of the CBECS.
We hope this letter and our recommendations are helpful to you in planning the 2011 CBECS.
Sincerely,
William F. Eddy
Chair
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