c-hat

[James A. Landau]

In a message dated 07/29/2002 10:26:36 AM Eastern Daylight Time,
susandgilbert at MSN.COM writes:

> Can anyone here tell me who coined the term Cultural-historical activity
>  theory, (CHAT) and where it first appeared in print? My earliest extant
> writing on this is Karl Marx in his Theses On Feuerbach (1845) where he
>  outlines his theory on object-oriented activity or labor.

I have no information on your question, but I would like to comment that your
terminology, to an engineer like me, is most strange.

"c-hat" is how a mathematically-trained person refers to the letter c with a
circumflex or caret over it.  The letter plus circumflex is used in
statistics to designate an estimate rather than an actual value (the theory
behind the distinction was first worked out in 1908 by "Student" (pseudonym
for W. S. Gosset), who made the discovery quite literally on company
time---he was a brewmaster for Guinness who had been sent to study statistics
under the elder Pearson.  The hat symbol was introduced by Pearson's great
rival Fisher in 1922).  In other branches of mathematics the hat symbol is
used to designate a conjectured number.  For example, early in this century
Brouwer defined the number "pi-hat" and devised a paradox based on whether
pi-hat exists.  To this day the paradox remains unsolved.

"object-oriented" (and the acronym "OOPS" for "object-oriented programming
system") has a highly specific meaning in computer programming.  (If you have
a rainy weekend, I'll explain it to you).  I don't know when the term "object
oriented" was invented in computer science, but it was a well-established
term by the late 1980's.

    - Jim Landau
      systems engineer
      FAA Technical Center (ACB-510/BCI)
     Atlantic City Int'l Airport NJ 08405 USA