The language curmudgeon . . .

Migrate is not a transitive verb

Conrad Weisert
© Information Disciplines, Inc., Chicago—1 December 2009

NOTE: This document may be circulated or quoted from freely, as long as the copyright credit is included.

In the 1970s we began to talk of "data migration" to describe the process by which computer files would move from online storage to an archival or backup medium. The obvious analogy was to the seasonal migration of birds or the occasional migration of groups of people. It was, of course, the data files that were doing the migration.

The term was later extended to the conversion of files or whole computer applications. The accounting system might migrate to a new machine. Although that usage strained the analogy with birds and populations it was still understandable.

But then the terminology changed. We began to see the word used in a transitive sense:

"We have to migrate all our data before January 1."

Now it wasn't the data files that were doing the migration; it was the staff doing it to the data files. That new usage was in conflict with the dictionary definitions of the word. Here's what the Que Programmer's Dictionary1 said about it in 1993:

  1. To move from an expensive (online fast-access) auxiliary storage medium to a less expensive (usually offline) medium, usually as a result of some automatically triggered procedure.
  2. To switch from the use of an old or obsolete version of a product of platform to a different or new version of a product or platform.
In both senses migrate is always intransitive. That is, data sets or files may migrate to archive storage or users may migrate to a new release of a word processor, but it is a misusage to speak of users migrating their files, programmers migrating applications, or a vendor migrating its customers.

Migrate often connotes multiple individual actions over an extended or indefinite time period. Avoid using the term as a synonym for either convert or move.

Nevertheless, such misusages persist, to the point where Microsoft's Encarta College Dictionary2 has capitulated. After three conventional definitions it offers this:

  1. v.t. MOVE BETWEEN COMPUTER SYSTEMS  to transfer a file from one computer system to another.

While I usually respect the Encarta, I strongly disagree here on the grounds of both precision in writing and necessity. This usage fills no need. Why not just use the more descriptive terms move, transfer, transmit, convert, etc.?

1—ISBN 1-56529-125-5
2—ISBN 0-312-28087-4

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Last modified 1 December 2009