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Digest of Education Statistics: 2007
Digest of Education Statistics: 2007

NCES 2008-022
March 2008

Appendix A.2. Integrated Postsecondary Education Data System

The Integrated Postsecondary Education Data System (IPEDS) surveys approximately 6,500 postsecondary institutions, including universities and colleges, as well as institutions offering technical and vocational education beyond the high school level. IPEDS, which began in 1986, replaced the Higher Education General Information Survey (HEGIS).

IPEDS consists of nine interrelated components that obtain information on who provides postsecondary education (institutions), who participates in it and completes it (students), what programs are offered and what programs are completed, and both the human and financial resources involved in the provision of institutionally based postsecondary education. Until 2000, these components included institutional characteristics, fall enrollment, completions, salaries, finance, and fall staff. Since 2000, data are collected in the fall for institutional characteristics and completions; in the winter for employees by assigned position (EAP), salaries, and fall staff; and in the spring for enrollment, student financial aid, finances, and graduation rates. With the winter 2005–06 survey, the employees by assigned position, fall staff, and salaries components were merged into the human resources component.

The degree-granting institutions portion of IPEDS is a census of colleges awarding associate's or higher degrees that are eligible to participate in Title IV financial aid programs. Prior to 1993, data from technical and vocational institutions were collected through a sample survey. Beginning in 1993, all data are gathered in a census of all postsecondary institutions. The tabulations on "institutional characteristics" developed for this edition of the Digest are based on lists of all institutions and are not subject to sampling errors.

The definition of institutions generally thought of as offering college and university education changed between FY 95 and FY 96. The old standard for higher education institutions included those institutions that had courses leading to an associate's or higher degree or that had courses accepted for credit toward those degrees. Higher education institutions were accredited by an agency or association that was recognized by the U.S. Department of Education or were recognized directly by the Secretary of Education. Tables, or portions of tables, that use only this standard are noted as "higher education" in the Digest. The newer standard includes institutions that award associate's or higher degrees and that are eligible to participate in Title IV federal financial aid programs. Tables that contain any data according to this standard are titled "degree-granting" institutions. Time-series tables may contain data from both series, and they are noted accordingly. The impact of this change on data collected in 1996 was not large. For example, tables on faculty salaries and benefits were only affected to a very small extent. Also, degrees awarded at the bachelor's level or higher were not heavily affected. The largest impact was on private 2-year college enrollment. In contrast, most of the data on public 4-year colleges were affected to a minimal extent. The impact on enrollment in public 2-year colleges was noticeable in certain states, but was relatively small at the national level. Overall, total enrollment for all institutions was about one-half a percent higher in 1996 for degree-granting institutions than for higher education institutions.

Prior to the establishment of IPEDS in 1986, HEGIS acquired and maintained statistical data on the characteristics and operations of institutions of higher education. Implemented in 1966, HEGIS was an annual universe survey of institutions accredited at the college level by an agency recognized by the Secretary of the U.S. Department of Education. These institutions were listed in NCES's Education Directory, Colleges and Universities.

HEGIS surveys collected information on institutional characteristics, faculty salaries, finances, enrollment, and degrees. Since these surveys, like IPEDS, were distributed to all higher education institutions, the data presented are not subject to sampling error. However, they are subject to nonsampling error, the sources of which varied with the survey instrument.

The NCES Taskforce for IPEDS Redesign recognized that there were issues related to the consistency of data definitions as well as the accuracy, reliability, and validity of other quality measures within and across surveys. The IPEDS redesign in 2000 provided institution-specific web-based data forms. While the new system shortened data processing time and provided better data consistency, it did not address the accuracy of the data provided by institutions.

Beginning in 2003–04 with the Prior Year Data Revision System, prior-year data have been available to institutions entering current data. This allows institutions to make changes to their prior-year entries either by adjusting the data or by providing missing data. These revisions allow the evaluation of the data's accuracy by looking at the changes made.

NCES conducted a study (NCES 2005-175) of the 2002–03 data that were revised in 2003–04 to determine the accuracy of the imputations, track the institutions that submitted revised data, and analyze the revised data they submitted. When institutions made changes to their data, it was assumed that the revised data were the "true" data. The data were analyzed for the number and type of institutions making changes, the type of changes, the magnitude of the changes, and the impact on published data.

Because NCES imputes missing data, imputation procedures were also addressed by the Redesign Taskforce. For the 2003–04 assessment, differences between revised values and values that were imputed in the original files were compared (i.e., revised value minus imputed value). These differences were then used to provide an assessment of the effectiveness of imputation procedures. The size of the differences also provides an indication of the accuracy of imputation procedures. To assess the overall impact of changes on aggregate IPEDS estimates, published tables for each component were reconstructed using the revised 2002–03 data. These reconstructed tables were then compared to the published tables to determine the magnitude of aggregate bias and the direction of this bias.

Though IPEDS provides the most comprehensive data system for postsecondary education, there are 100 or more entities that collect their own information from postsecondary institutions. This raises the issue of how valid IPEDS data are when compared to education data collected by non-IPEDS sources. In the Data Quality Study, Thomson Peterson data were chosen to assess the validity of IPEDS data, because Thomson Peterson is one of the largest and most comprehensive sources of postsecondary data available.

Not all IPEDS components could be compared to Thomson Peterson. Either Thomson Peterson did not collect data related to a particular IPEDS component, or the data items collected by Thomson Peterson were not comparable to the IPEDS items (i.e., the data items were defined differently). Comparisons were made for a selected number of data items in five areas—tuition and price, employees by assigned position, enrollment, student financial aid, and finance. More details on the accuracy and reliability of IPEDS data can be found in the Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175).

Further information on IPEDS may be obtained from

Elise Miller
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
Elise.Miller@ed.gov
http://nces.ed.gov/ipeds/

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Fall (Completions)

This survey was part of the HEGIS series throughout its existence. However, the degree classification taxonomy was revised in 1970–71, 1982–83, 1991–92, and 2002–03. Collection of degree data has been maintained through IPEDS.

Degrees-conferred trend tables arranged by the 2002–03 classification are included in the Digest to provide consistent data from 1970–71 to the most recent year. Data in this edition on associate's and other formal awards below the baccalaureate degree, by field of study, cannot be made comparable with figures from prior to 1982–83. The nonresponse rate does not appear to be a significant source of nonsampling error for this survey. The response rate over the years has been high, with the degree-granting institution response rate for the fall 2005 survey at 99.7 percent. The overall response rate for non-degree-granting institutions was 99.1 percent in fall 2005. The response rate is lower than last year due to the natural disasters of fall 2005; the data for 20 institutions unable to respond were imputed. Because of the high response rate for degree-granting institutions, nonsampling error caused by imputation is also minimal. Imputation methods and the response bias analysis for the fall 2005 survey are discussed in Postsecondary Institutions in the United States: Fall 2005 and Degrees and Other Awards Conferred: 2004–05 (NCES 2007-167).

The Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175) indicated that most Title IV institutions supplying revised data on completions in 2003–04 were able to supply missing data for the prior year. The small differences between imputed data for the prior year and the revised actual data supplied by the institution indicated that the imputed values produced by NCES were acceptable.

Further information on the IPEDS Completions survey may be obtained from

Andrew Mary
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
Andrew.Mary@ed.gov
http://nces.ed.gov/ipeds/

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Fall (Institutional Characteristics)

This survey collects the basic information necessary to classify institutions, including control, level, and types of programs offered, as well as information on tuition, fees, and room and board charges. Beginning in 2000, the survey collected institutional pricing data from institutions with first-time, full-time, degree/certificate-seeking undergraduate students. Unduplicated full-year enrollment counts and instructional activity are now collected in the Fall Enrollment survey. The overall response rate was 99.9 percent for Title IV degree-granting institutions for 2005 data.

The Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175) looked at tuition and price in Title IV institutions. Only 8 percent of institutions in 2002–03 and 2003–04 reported the same data to IPEDS and Thomson Peterson consistently across all selected data items. Differences in wordings or survey items may account for some of these inconsistencies.

Further information on the IPEDS Institutional Characteristics survey may be obtained from

Frank Morgan
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
Frank.Morgan@ed.gov
http://nces.ed.gov/ipeds/

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Winter (Fall Staff)

The fall staff data presented in this publication were collected by NCES through IPEDS, which collects data from postsecondary institutions, including all 2- and 4-year degree-granting education institutions. IPEDS collects staff data biennially, in odd numbered years.

Questionnaires for the 2005–06 Fall Staff survey were completed on the IPEDS data collection website between December 2005 and January 2006; respondents report employment statistics for their institution that cover the payroll period in the fall of the survey year. The 2005–06 survey had an overall response rate of 99.9 percent and a response rate of 99.9 percent for both degree-granting institutions and for non-degree-granting institutions. Imputation methods and the response bias analysis for the 2005–06 Fall Staff survey are discussed in Employees in Postsecondary Institutions, Fall 2005, and Salaries of Full-Time Instructional Faculty, 2005-06 (NCES 2007-150).

The most recent data quality study, Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175), found that for 2003–04 employee data items, changes were made by 1.2 percent (77) of the institutions that responded. All who made changes made changes that resulted in different employee counts. For both institutional and aggregate differences, the changes had little impact on the original employee count submissions. A large number of institutions reported different staff data to IPEDS and Thomson Peterson; however, the magnitude of the differences was small—usually no more than 17 faculty members for any faculty variable.

Further information on the Fall Staff survey may be obtained from

Sabrina Ratchford
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
Sabrina.Ratchford@ed.gov
http://nces.ed.gov/ipeds/

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Winter (Salaries, Tenure, and Fringe Benefits of Full-time Instructional Faculty)

This institutional survey was conducted for most years from 1966–67 to 1987–88; it has been conducted annually since 1989–90, except for 2000–01. Although the survey form has changed a number of times during these years, only comparable data are presented.

Between 1966–67 and 1985–86, this survey differed from other HEGIS surveys in that imputations were not made for nonrespondents. Thus, there is some possibility that the salary averages presented in this report may differ from the results of a complete enumeration of all colleges and universities. Beginning with the surveys for 1987–88, the IPEDS data tabulation procedures included imputations for survey nonrespondents. The response rate for the 2005–06 survey was 99.9 percent for degree-granting institutions. A number of institutions affected by Hurricanes Rita and Katrina did not respond and their data were not imputed. Imputation methods and the response bias analysis for the 2005–06 survey are discussed in Employees in Postsecondary Institutions, Fall 2005, and Salaries of Full-Time Instructional Faculty, 2005–06 (NCES 2007-150). Although data from these surveys are not subject to sampling error, sources of nonsampling error may include computational errors and misclassification in reporting and processing. The electronic reporting system does allow corrections to prior-year reported or missed data and this should help with these problems. Also, NCES reviews individual institutions' data for internal and longitudinal consistency and contacts institutions to check inconsistent data.

The Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175) found that only 1.3 percent of the responding Title IV institutions in 2003–04 made changes to their salaries data. The imputations made in the original publication proved to be acceptable when the revised data indicated small differences, and therefore had little impact on the published data.

Further information on the Salaries, Tenure, and Fringe Benefits survey may be obtained from

Sabrina Ratchford
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
Sabrina.Ratchford@ed.gov
http://nces.ed.gov/ipeds/

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Winter/Spring (Fall Enrollment)

This survey has been part of the HEGIS and IPEDS series since 1966. Response rates for this survey have been relatively high, generally exceeding 85 percent. Beginning in 2000, with web-based data collection, higher response rates were attained. In 2005–06, the overall response rates were 100.0 percent for degree-granting 4-year private not-for-profit institutions, 2-year public institutions, and 2-year private not-for-profit institutions; the response rate was 99.8 percent for 4-year public institutions. Imputation methods and the response bias analysis for the 2005–06 survey are discussed in Enrollment in Postsecondary Institutions, Fall 2005; Graduation Rates, 1999 & 2002 Cohorts; and Financial Statistics, Fiscal Year 2005 (NCES 2007-154).

Beginning with the fall 1986 survey and the introduction of IPEDS (see above), the survey was redesigned. The survey allows (in alternating years) for the collection of age and residence data. Beginning in 2000, the survey collected instructional activity and unduplicated headcount data, which are needed to compute a standardized, full-time-equivalent (FTE) enrollment statistic for the entire academic year.

The Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175) showed that public institutions made the majority of changes to enrollment data during the 2004 revision period. The majority of changes were made to unduplicated headcount data, with the net differences between the original data and the revised data at about 1 percent. Part-time students in general and enrollment in private not-for-profit institutions were often underestimated. The fewest changes by institutions were to Classification of Instructional Programs (CIP) code data. (The CIP is a taxonomic coding scheme that contains titles and descriptions of primarily postsecondary instructional programs.) More institutions provided enrollment data to IPEDS than to Thomson Peterson. A fairly high percentage of institutions that provided data to both provided the same data, and among those that did not, the difference in magnitude was less than 10 percent.

Further information on the IPEDS Fall Enrollment survey may be obtained from

Frank Morgan
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
frank.morgan@ed.gov
http://nces.ed.gov/ipeds

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Spring (Finance)

This survey was part of the HEGIS series and has been continued under IPEDS. Substantial changes were made in the financial survey instruments in fiscal year (FY) 1976, FY 82, FY 87, FY 97, and FY 02. While these changes were significant, considerable effort has been made to present only comparable information on trends in this report and to note inconsistencies. The FY 76 survey instrument contained numerous revisions to earlier survey forms, which made direct comparisons of line items very difficult. Beginning in FY 82, Pell Grant data were collected in the categories of federal restricted grant and contract revenues and restricted scholarship and fellowship expenditures. Finance tables for this publication have been adjusted by subtracting the largely duplicative Pell Grant amounts from the later data to maintain comparability with pre-FY 82 data. The introduction of IPEDS in the FY 87 survey included several important changes to the survey instrument and data processing procedures. Beginning in FY 97, data for private institutions were collected using new financial concepts consistent with Financial Accounting Standards Board (FASB) reporting standards, which provide a more comprehensive view of college finance activities. The data for public institutions continued to be collected using the older survey form. The data for public and private institutions were no longer comparable and, as a result, no longer presented together in analysis tables. Beginning in FY 01, public institutions had the option of either continuing to report using Government Accounting Standards Board (GASB) standards or using the new FASB reporting standards. Beginning in FY 02, public institutions had three options: the original GASB standards, the FASB standards, or the new GASB Statement 35 standards (GASB35). Because of the complexity of the multiple forms used by public institutions, finance data for public institutions for some recent years are not presented in the Digest.

Possible sources of nonsampling error in the financial statistics include nonresponse, imputation, and misclassification. The response rate has been about 85 to 90 percent for most of the historic years presented in the Digest; however, in more recent years, response rates have been much higher because Title IV institutions are required to respond. The 2002 IPEDS data collection was a full-scale web-based collection, which offered features that improved the quality and timeliness of the data. The ability of IPEDS to tailor online data entry forms for each institution based on characteristics such as institutional control, level of institution, and calendar system, and the institutions' ability to submit their data online, were two such features that improved response. The response rate for the FY 05 Finance survey was 99.9 percent for degree-granting institutions. The response rates were 100.0 percent for public 2-year and private not-for-profit 2-year institutions, while the response rates were 99.9 percent for public 4-year and private not-for-profit 4-year institutions. Imputation methods and the response bias analysis for the FY 05 survey are discussed in Enrollment in Postsecondary Institutions, Fall 2005; Graduation Rates, 1999 & 2002 Cohorts; and Financial Statistics, Fiscal Year 2005 (NCES 2007-154).

Two general methods of imputation were used in HEGIS. If prior-year data were available for a nonresponding institution, they were inflated using the Higher Education Price Index and adjusted according to changes in enrollments. If prior-year data were not available, current data were used from peer institutions selected for location (state or region), control, level, and enrollment size of institution. In most cases, estimates for nonreporting institutions in HEGIS were made using data from peer institutions.

Beginning with FY 87, IPEDS included all postsecondary institutions, but maintained comparability with earlier surveys by allowing 2- and 4-year institutions to be tabulated separately. For FY 87 through FY 91, in order to maintain comparability with the historical time series of HEGIS institutions, data were combined from two of the three different survey forms that make up IPEDS. The vast majority of the data were tabulated from form 1, which was used to collect information from public and private not-for-profit 2- and 4-year colleges. Form 2, a condensed form, was used to gather data for 2-year for-profit institutions. Because of the differences in the data requested on the two forms, several assumptions were made about the form 2 reports so that their figures could be included in the degree-granting institution totals.

In IPEDS, the form 2 institutions were not asked to separate appropriations from grants and contracts, nor were they asked to separate state from local sources of funding. For the form 2 institutions, all federal revenues were assumed to be federal grants and contracts, and all state and local revenues were assumed to be restricted state grants and contracts. All other form 2 sources of revenue, except for tuition and fees and sales and services of educational activities, were included under "other." Similar adjustments were made to the expenditure accounts. The form 2 institutions reported instruction and scholarship and fellowship expenditures only. All other educational and general expenditures were allocated to academic support.

The Integrated Postsecondary Education Data System Data Quality Study (NCES 2005-175) found that only a small percentage (2.9 percent, or 168) of postsecondary institutions either revised 2002–03 data or submitted data for items they previously left unreported. Though relatively few institutions made changes, the changes made were relatively large—greater than 10 percent of the original data. With a few exceptions, these changes, large as they were, did not greatly affect the aggregate totals.

Again, institutions were more likely to report data to IPEDS than to Thomson Peterson, and there was a higher percentage reporting different values among those reporting to both. The magnitude of the difference was generally greater for research expenditures. It is likely that the large differences are a function of the way institutions report these data to both entities.

Further information on the IPEDS Finance survey may be obtained from

Elise Miller
Postsecondary Studies Division
Postsecondary Institutional Studies Program
National Center for Education Statistics
1990 K Street NW
Washington, DC 20006
elise.miller@ed.gov
http://nces.ed.gov/ipeds