skills and strategies. He demonstrated this in the case of children's performance on conservation tasks over time. Development Since the concept of cumulative learning was first written about by Gagné, there have been great advances in the understanding of it. Cumulative learning is a hallmark of human cognition, offering an integrated view of processes that have been previously treated in isolation. At the heart of it is unification - new information is integrated by default with already acquired knowledge. There are 14 dimensions which determine the performance characteristics of cumulative learning implementation, separated into three groupings: memory management, temporal capacity and granularity, and generality. Each of these areas help to identify just how cumulative learning works in practice. An ideal cumulative learner should be capable of learning multiple things consecutively, accumulating knowledge in any situation and being able to use it in unforeseen future contexts. Other works have noted that cumulative learning allows a learner to acquire knowledge through four processes: activating existing schema relevant for new information, concretely generalising the given information, extracting commonalities and reorganising the information in the cognitive structure accordingly. Whilst they appear to differ slightly from the ones mentioned above, they are referring to the same processes in principle. Once they have acquired new information, learners try to incorporate it into their existing knowledge structures with these new cognitive structures - then interact cumulatively with further learning situations. A further two cognitive processes are identified as being inherent to cumulative learning - aggregation and abstraction. Aggregation is where a learner extracts and identifies information into a coherent knowledge structure, and abstraction is the process of extracting commonalities from the underlying structure of knowledge and created mental models. Learners can also use a combination of both to assist their knowledge retention and utilisation. Application The concept of cumulative learning can, and has been, applied to real-world situations. A very simple example is the saying 'you can't run before you can walk'; the procedural memory built while learning to walk is necessary before one can start to learn to run. Pronouncing words is impossible without first learning to pronounce the vowels and consonants that make them up (hence babies' babbling). This is an essential cognitive capacity, allowing prior development to produce new foundations for further cognitive development. There is plenty of literature surrounding the use of cumulative learning in artificial intelligence and machine learning. Artificially general intelligent