At
the
end
of
the
2010-‐2011
school
year,
data
on
teaching
practices
and
perceptions
were
systematically
gathered
and
compared
from
two
groups
of
teachers
matched
by
demographics,
grade
and
subject:
teachers
expected
to
have
utilized
PBL
after
extended
professional
development
(44)
and
teachers
who
had
not
received
the
professional
development
or
were
not
expected
to
have
used
PBL
(42).