might look for whether the child introduces characters to their story or jumps right in, whether the events follow a logical order, and whether the narrative includes a main idea or theme and supporting details. intervention intervention is usually carried out by speech and language therapists, who use a wide range of techniques to stimulate language learning. in the past, there was a vogue for drilling children in grammatical exercises, using imitation and elicitation methods, but such methods fell into disuse when it became apparent that there was little generalisation to everyday situations. contemporary approaches to enhancing development of language structure are more likely to adopt 'milieu' methods, in which the intervention is interwoven into natural episodes of communication, and the therapist builds on the child's utterances, rather than dictating what will be talked about. in addition, there has been a move away from a focus solely on grammar and phonology toward interventions that develop children's social use of language, often working in small groups that may include typically developing as well as language-impaired peers. another way in which modern approaches to remediation differ from the past is that parents are more likely to be directly involved, particularly with preschool children. a radically different approach has been developed by tallal and colleagues, who have devised a computer-based intervention, fast forword, that involves prolonged and intensive training on specific components of language and auditory processing. the theory underlying this approach maintains that language difficulties are caused by a failure to make fine-grained auditory discriminations in the temporal dimension, and the computerised training materials are designed to sharpen perceptual acuity. for all these types of intervention, there are few adequately controlled trials that allow one to assess clinical efficacy. in general, where studies have been done, results have been disappointing, though some more positive outcomes have been reported. in 2010, a systematic review of clinical trials assessing the fastforword approach was published, and reported no significant gains relative to a control group. outcome longitudinal studies indicate that problems are largely resolved by five years in around 40% of 4-year-olds with sli. however, for children who still have significant language difficulties at school entry low levels of literacy are common, even for children who receive specialist help, and educational attainments are typically poor. poor outcomes are most common in cases where comprehension as well as expressive language is affected. there is also evidence that the nonverbal iq of children with sli decreases over the course of development. sli is associated with a high rate of psychiatric disorder. for instance, conti-ramsden and botting (2004) found that 64% of a sample of 11-year-olds with sli scored above a clinical threshold on a questionnaire for psychiatric difficulties, and 36% were regularly bullied, compared with 12% of comparison children. in the longer-term, studies of adult outcomes of children with sli find elevated rates of unemployment, social isolation and psychiatric disorder. however, most studies focused on children with severe problems, where comprehension as well as expressive language was affected. better outcomes are found for children who have milder difficulties and do not require special educational provision. prevalence epidemiological surveys, in the us and canada, estimated the prevalence of sli in five-year-olds at around 7%. however, neither study adopted the stringent "discrepancy" criteria of the diagnostic and statistical manual of mental disorders or icd-10; sli was diagnosed if the child scored below cut-off on standardized language tests, but had a nonverbal iq of 90 or above and no other exclusionary criteria. research much research has focused on trying to identify what makes language learning so hard for some children. a major divide is between theories that attribute the difficulties to a low-level problem with auditory temporal processing, and those that propose there is a deficit in a specialised language-learning system. other accounts emphasise deficits in specific aspects of memory. it can be difficult to choose between theories because they do not always make distinctive predictions, and there is considerable heterogeneity among children with sli. it has also been suggested that sli may only arise when more than one underlying deficit is present.