  A variety of activities are commonly used in college physics courses
including lab, tutorials, and studio curricula. Instructors must choose among
using research-based activities, designing their own activities or modifying
existing activities. Instructors' choices depend on their own goals and the
goals of activities from which they are choosing. To assist them in developing
or modifying activities for their situation, we examine research-based
activities to determine their goals and the features of the activities
associated with these goals. Since most activities ask students to perform
tasks to assist them in learning, sixty-six activities from eleven different
research-based curricula were coded for student actions. The coding scheme
containing forty-nine codes in ten categories was developed from a subset of
activities, interviews with some of the activity designers, and recommendations
from the American Association of Physics Teachers 2014 lab report. The results
were examined using k-means cluster analysis revealing three design clusters.
We label these clusters Thinking like a Scientists, Learning Concepts, Building
Models. These three clusters reflect diverse design goals. In the Thinking like
a Scientist cluster, activities emphasize design of experiments by students,
discussion, error analysis, reasonableness checking, supporting claims, and
making assumptions or simplifications. The Learning Concepts cluster focuses on
prediction of results and experimental observations. The Building Models
cluster emphasizes discussion and answering physics or math questions that do
not use collected data. This work connects common features appearing in physics
activities with the goals and strategies of the designers. In this way it may
provide instructors with a more straightforward way to creat activities which
achieve their desired outcomes.
