The definitions of these two descriptive learning conditions are particularly UK based and need explaining. Such explanations could take up a book in themselves if we were to do the subject full justice, though (like the rest of the book) we will try to be brief and to the point. The UK definition is largely based on observation of broadly definable (group) characteristics that practitioners understand as defining SLD. These characteristics have been noted by Imray (2005) as being difficulties with communication, understanding abstract concepts, concentration, and moving things from the short-term memory to the long. Lacey (2009) has noted that this group of learners typically have inefficient and slow informationprocessing speeds, little general knowledge, poor strategies for thinking and learning, and difficulties with generalisation and problem solving. These difficulties may well be compounded by considerably higher than usual incidence of sensory, motor and health difficulties (Porter, 2005b); an additional Autistic Spectrum Condition (ASC) diagnosis (Jordan, 2001; De Bildt et al., 2005); and the considerably higher than average chance of having attendant challenging behaviours (Emerson, 1995; Harris, 1995; Male, 1996; Allen et al., 2006). Interestingly, Carpenter (2010) has noted an increasing complexity of learning difficulties since the turn of the twentieth-first century, an observation also noted by a recent UK Special Educational Needs and Disabilities (SEND) Review, which reported special school headteachers’ comments on this issue (Ofsted, 2006).