Specific learning difficulties often occur in people of average or above average intelligence and they involve problems with one or more of the basic processes used in understanding or using spoken or written language. Examples of SLD's are dyslexia, dyspraxia and dyscalculia. Difficulties experienced may include problems with word recognition, aspects of reading comprehension, and aspects of writing and/or spelling. The exact nature and extent of these difficulties will vary from one student to another. SLD's have only recently been identified and still often go undiagnosed. Although described as separate conditions, they usually in fact overlap with one another, and most people with specific learning difficulties will experience more than one condition. There are three to four time more common amongst men than women and people who have experienced them are generally of an average or above average intelligence.;