Published in Nunes,T (ed) Special Issue, ‘Giving Meaning to Mathematical Signs: Psychological,
Pedagogical and Cultural Processes‘ Human Development, Vol 52, No 2, April, pp. 129-
on the chart, and plot the graphical elements by hand: these charts are then handed
over to the process engineers, who undertake a series of complex calculations to
produce measures of efficiency (shown in the bottom right corner of Fig 2), which
become the subject of discussion at team meetings.
Figure 2. An example of an SPC chart, an intended boundary object
Our ethnography derived some understanding of how the charts were used,
what they were intended to do, and the kinds of technomathematical knowledge
necessary for their effective interpretation. In the pedagogic phase of our work we
enhanced the charts electronically: in fact, this became a general methodological
gambit and we coined the term “technologically enhanced boundary object, or TEBO,
to describe the designed artefact. The idea was straightforward: to open up some of
the layers of mathematical structure hidden in the artefact, sometimes by opening
black-boxed calculations to reveal key variables, and in other cases (as in this
example), by outsourcing to our TEBO some of what the employees previously had to
understand.
In the SPC training provided by the factory, we had observed trainees
engaging in physical experiments catalysed by a version of a —shove ha’penny” game
in order to generate sample process data7. By a set of various improvements in
7 Shove ha‘penny is a British game that used to be played in pubs, in which coins are pushed
or flicked up a graduated horizontal board, and bets cast as to where they will land.
11