I encourage any reader to review all five domains of learning rather than simply one. They work only when used in combination to achieve a balance in the students' learning experience, in their development of complementary skills.
Bloom et.al's original cognitive taxonomy (1956) was the result of a project to define the educational psychological parameters of three distinct domains, the cognitive, affective and psychomotor. Although not explicitly designed for compulsory education (K-12) it has proved easily comprehensible by most teachers and so has been widely adopted and adapted. In my personal view, it has always been more suitable to tertiary and professional educational contexts although it has a number of shortcomings. In both its tabular form or its classical pyramidic representation it implies levels, in which one must master a particular skill before graduating onto the next. I believe there is a degree of progression, which makes sense to practising faculty, but the movement between these categories, or segments, is not a straight line. Circular representations are more fluid and flexible.
The second criticism of Bloom's original domain was that it was based on rather thin empirical data. My circular representations are not intended to describe theory but rather the enable practice and I am satisfied, as are many practitioners, that our practice is recognisable in the broadly progressive nature of different segments.
In 2001, Bloom's students and collaborators ( Anderson et.al, 2001) revisited the original cognitive taxonomy and made two significant alterations. They expanded on Bloom's original 'knowledge dimension' which introduced four further filters through which their six 'cognitive process dimension' could be articulated. Bloom's original work made mention of factual, conceptual and procedural knowledge, the 2001 team added metacognition. This produces 24 individually defined 'data-points'. Their intention was largely to assist school-based educators working towards a standard curriculum. My intention is to support the most flexible learning design possible in tertiary and professional contexts and so I have articulated a metacognitive domain which captures their knowledge dimension and expands it further. A second alteration was to use active rather than passive language (application to apply/applying), as I have done across all five domains, and a third was the shift from 'knowledge' in 1956 to 'remembering' in 2001, and to reverse the last two levels from synthesis and evaluation (1956) to evaluating and creating.
Bloom noted early on that his 'knowledge' level was of a different order of magnitude. In my cognitive domain represnetation, I have chosen to compound both the 2001's levels of remembering and understanding and the 1956's levels of knowledge and comprehension into a single segment entitled 'Remember and Understand'. I believe this is appropriate in a tertiary context, other work might helpfully reinterpret this segment through a more appropriate K-12 filter, such as Gardners 'Multiple Intelligences' (2011), but that is for another time. My broad definition of this category or segment is an "ability to recognise information and comprehend it and to recall and restate said information." This falls short of Bloom's original notion of comprehension as representing an ability to grasp or construct, meaning from the material, or Anderson's concept of understanding as denoting the construction of meaning. I believe such definitions only make sense when viewed through the four filters in their knowledge dimension. In creating a separate domain for metacognitioon I provide tools for learning designers to precisely articulate metacognitive skills. My initial cognitive segment, therefore, is simplified and describes primarily the ability to identify that something represents knowledge and recall it at a later date.