For this research, qualitative methodology was applied with an emphasis on the three-year observational study based on
Begle’s conceptual framework (1969) with ways of observation
and consideration on studying the nature of occurrences which
starts with extensive, careful, and empirical observations of
mathematics teaching and learning. In 2008 and 2009, any
trends noted in these observations would lead to the formulation
of hypotheses. In 2010, these hypotheses could then be
checked against further observations and refined and sharpened.
There was data collection in the learning unit on “addition (2)”,
the first activity “Children playing in sandboxes and on slides”
and the second activity “Buying eggs to make omelets”, which
were developed from the lesson study process. All important
qualitative data came from class observations, video recording
while students were solving problems, field notes, and students’
written works which were analyzed. This process was based on
triangulation from three data sources: video recording while
students were solving problems, field notes, and analyzing students’
written works