I have a question about a case I am working on for my essay, can you help me? The description of the case is here below: In the case, a girl of 3,5 years is described who has speech problems. She does not really talk and only makes random sounds. She receives help from a speech therapist, but she doesn't seem to benefit from it. According to the parents, their daughter does understand what words mean and she does talk a little at home. The girl goes to a daycare where they speak English, at home with her parents she talks Spanish.
First things first: based on this limited information it is really difficult to pinpoint the exact problem. But what we can do is come up with some hypotheses about what could cause the problem. The first thing that comes to mind is that the girl is being raised bilingual. In bilingual children, it's prevalent that they first can have a "disadvantage" compared to unilingual children but when they get a little older they get an advantage (e.g. McLaughlin, 2011). This means that at first bilingual children know and use fewer words than unilingual children, but later on, bilingual children can use two full languages and unilingual use one full language. It takes more effort and time to learn two languages at once, but it pays off in the end. Therefore this could be one explanation to the case you described. A second explanation could be that the girl has a hearing problem. This sometimes sounds like an "out of the blue" hypothesis, but it's always good to be sure that the problems are not caused by difficulties in hearing. Because, if the girl has hearing problems it is difficult for her to hear the words and repeat them correctly (Asha, 2019). A third explanation could be DSM-V mental health problems: e.g. autism, down syndrome, low IQ (American Psychiatric Association, 2008). This could be determined by using clinical research to determine and/or exclude DSM-V characteristics. Because the girl is only 3,5 years old, I personally think that is too young to conduct clinical research. Therefore I would be mindful of other mental health issues and follow closely if the behaviour shown by the girl is age-appropriate. So, in short: we have three possible explanations of which the third explanation is a very broad one. In the field this is the same way I would handle the case: 1. does the child speak multiple languages? 2. does the child have hearing difficulties? 3. could the behaviour - although 3,5 years is in my opinion in most cases too young to diagnose - be explained by DSM-V characteristics? Hopefully, I helped you along with the thought process and good luck with your essay! Literature: Asha. (2019). Effects of Hearing Loss on Development. From: https://www.asha.org/public/hearing/effects-of-hearing-loss-on-development/. American Psychiatric Association. (2008). DSM-V The Future Manual. Archived from the original on 19 November 2008. McLaughlin, M. R. (2011). Speech and Language Delay in Children. American Academy of Family Physicians, from www.aafp.org/afp.
For my assignment, I have to do a t-test, but I do not understand if I should choose a one-sample t-test or a two-sample t-test. Can you explain to me the difference between the two and help me choose between the one-sample t-test and two-sample t-test?
For the answer on this question, we are going to focus on the one-sample and two-sample part of the question, because you already determined that you wanted to do a t-test. The difference between the one-sample and the two-sample is the type of group or groups you have. Because to be able to do a t-test, you need to compare two sets of groups with each other. These two sets of groups can be built up in two ways: - One group being used twice (e.g. a psychology exam and a psychology re-examination that is done by the same group, comparing if the students get a higher grade at the re-examination) - Two groups being used once (e.g. a psychology exam being taken by psychology and sociology students, comparing which students perform better on the psychology exam) So in short: When your data consist of one group of people used twice --> one-sample t-test When your data consist of two groups of people used once --> two-sample t-test