What IPEDS is
The Integrated Postsecondary Education Data System is the U.S. Department of Education’s primary collection for colleges, universities, and technical and vocational institutions. The National Center for Education Statistics publishes complete survey files as zipped CSV downloads and supplies a data dictionary for interpreting each file.
Rate Archive uses the official Complete Data Files catalog, not search snippets or third-party copies. The official download guide explains that dictionaries define field names, formatting, business rules, and relationships.
The files in the initial archive
| File family | What Rate Archive reads | Public status |
|---|---|---|
| HD | Institution identity and directory metadata, including UNITID. | Source metadata only |
| DRVEF | Enrollment used to define the initial high-enrollment coverage set. | Coverage metadata only |
| IC2000_AY–IC2023_AY | Rolling combined published tuition and required-fee history. | Validated, not publishable |
| COST1_2024 | Separately reported tuition and mandatory-fee components for four academic years. | Validated, not publishable |
Why a single annual file contains several years
The IC_AY CHG fields form a rolling window. In IC2000_AY, suffixes 1, 2, and 3 map to academic years 1998-99, 1999-00, and 2000-01. Beginning with the later layout, suffix 0 adds a fourth year. The adapter calculates each period from the collection year and suffix, then validates the mapping against required headers before accepting any row.
Repeated windows are valuable: a later release may revise an earlier value or imputation code. They are also dangerous if a pipeline silently deduplicates by academic year. Rate Archive preserves every selected release observation and links the later one to the observation it supersedes.
Original and revised members
Some official ZIPs contain both a base CSV and an _rv.csv member. For 2009, 2010, and 2011, Rate Archive selects the revised member, records that decision in the manifest, and retains the complete official ZIP. Years with one supplied member are labeled as single/original rather than being called “final” without evidence.
Preliminary, provisional, revised, single-member, and direct institutional records are never collapsed into an unlabeled “latest” value.
Imputation and missing values
X-prefixed fields preserve the official imputation or status code beside the substantive field. Blank cells and the period character used as a numeric missing sentinel remain gaps. They do not become zero. Rate Archive records the gap class so missing source data can be distinguished from an absent institution row.
Verified Stage 1B coverage
The first historical pass verifies 24 annual data ZIPs and 24 matching dictionary ZIPs from 2000 through 2023. Together they cover rolling academic years from 1998-99 through 2023-24 for the top-200 coverage set where records exist. The public site exposes the source map and methodology while all substantive observations remain behind the publication gate.
Browse the institution source directory or inspect the complete archive methodology.