75Boundaries, objects, brokers and crossings are generative conceptual ideas from
which to analyse professional experience. According to Akkerman and Bakker
( 2011 ):
a boundary can be seen as a sociocultural difference leading to discontinuity in action or
interaction. Boundaries simultaneously suggest a sameness and continuity in the sense that,
within discontinuity, two or more sites are relevant to one another in a particular way.
(p.133)
Tsui and Law ( 2007 ) suggest the way to overcome contradictions between super-
vising teachers and tertiary mentors is to create a space where all participants can
generate collective knowledge by crossing community boundaries in the profes-
sional experience. This third space creates conditions for boundary crossing
(Akkerman & Bakker, 2011 ). Engeström, Engeström, and Kärkkäine ( 1995 ) argue
that the negotiation and the use of the boundary object potentially facilitate bound-
ary crossing. Akkerman and Bakker ( 2011 ) call for further exploration of the learn-
ing potential of boundaries.
In this chapter, we use third-generation Cultural Historical Activity Theory
(CHAT) because it offers an understanding of the third space of the partnership
between the university and school where professional experience resides. This
chapter further develops Bloomfield and Nguyen’s ( 2015 ) proposed theoretical
framework for professional experience partnerships based on third-generation
CHAT (see Fig. 5.3). Bloomfield and Nguyen argue that the primary focus of such
a partnership is on developing a collective ‘third space’ (Bhabha, 1994 ; Gutierréz,
2008 ) which renegotiates and accommodates different elements of the two systems.
In this case study of preservice teachers’ learning in a ‘boundary zone’ (Tuomi-
Gröhn & Engeström, 2003 ), the focus was on the space where the participants in
both activity systems brokered their boundary objects to construct new understand-
ing and practices.
The boundary broker is a critical actor in third-generation CHAT. The broker’s
role has been depicted as that of the interlocutor (Kimble et al., 2010 ). Wenger
( 1998 ) described it in the following way:
Fig. 5.2 Two interacting activity systems as a minimal model for third generation of activity the-
ory (Engeström, 2001 , p. 136)
5 Boundary Objects and Brokers in Professional Experience