The effectiveness of dimethylglycine (DMG) as a dietary supplement and adjunct treatment to PECS approach in treating children with autism spectrum disorders and severe speech delay.

... In general, case studies are a preferred strategy when 'how' or 'why' questions are being posed, when the investigator has little control over events, and when the focus is on a contemporary phenomenon within some real-life context" (Yin, 2009). This article will examine the advantages and disadvantages of employing case study methodology in special educational settings. ...

... However, in studies where no other cases are obtainable for duplication, the researcher is restricted to a unit case plan. Yin (2009) urges that an overview of outcome, from either a unit or multiple designs, "is made to theory and not to populations." Multiple cases reinforce the consequences by duplicating the pattern, hence increasing assurance in the strength of the theory (McIntosh et al., 2013). ...

... In open-ended interviews, the interviewer asks about the common events and can suggest solutions or provide insights into measures. However, the research should avoid dependence on one interviewer but rather seek information from as many people as possible to verify its accuracy (Yin, 2009). In cases where the respondent is to be interviewed a short time this type of interview is used. ...

... DMG lowers the mortality rate in rodents with penicillin and strychnine-induced seizures (Freed, 1985;Ward et al., 1985). In addition, the beneficial effect of DMG has been revealed in young children with autism spectrum disorders (Chia, 2009;Xia, 2011). DMG might have the potential in treatment of certain neurological disorders. ...