However, such an approach to defining a curriculum is increasingly problematic on at least two fronts. First, there is an ever–growing list of courses that are arguably "core" courses, such as geobiology, paleoclimatology, etc. At the same time, many argue that the traditional core courses remain just as important as ever. Given that the number of courses a student can take is more or less fixed, this approach to defining a curriculum ultimately leads to a reduction in the number of elective courses a student can take and the irresolvable problem of what constitutes a modern set of "core" courses. Second, focusing on individual core courses does not, by itself, shed light on how the different courses interact pedagogically. Oftentimes, each course is designed to optimize learning in that specific field irrespective of what skills are covered or absent in other courses.
We have developed an alternative to the "core course" approach which might be described as a "core competencies" approach. We instituted this alternative approach to curricula design in 2009 and published an assessment of it in 2014 (Design and Assessment of a Skills-Based Geoscience Curriculum, Journal of Geoscience Education 62:668-678).
In our revised curriculum, instead of defining our curricula as a list of specific courses, we instead define multiple sets of key concepts or skills we want our graduates to master. These sets of core competencies reflect, in part, the on-going effort within the earth science community to define the core ideas and supporting concepts that constitute what everyone should know about earth sciences (see http://www.earthscienceliteracy.org/). For each set of key concepts and skills we have identified multiple courses that all include these key concepts and skills and require our students to take at least one of these courses.