A researcher wants to study the effect of vitamin D intake o…

A researcher wants to study the effect of vitamin D intake on muscle strength. She randomly assigns subjects to either an experimental group who receive Vitamin D supplementation or a control group who are given a placebo pill that does not contain any active ingredient. She measures subjects’ muscle strength before beginning supplementation and then 6 months after the subjects had been receiving daily supplementation. This is an example of:

Mirbagher-Ajorpaz and colleagues (2011) hypothesized that an…

Mirbagher-Ajorpaz and colleagues (2011) hypothesized that an acupressure intervention would decrease dysmenorrheal among female medical science students. They divided the sample of female medical science students into two groups – one group received the acupressure intervention and the other group did not receive any intervention. What statistical test, from the following list, would be the most appropriate to use to compare the mean dysmenorrhea scores of the intervention and control groups?

A researcher studied how much time parents spent playing wit…

A researcher studied how much time parents spent playing with their children with disabilities. The dependent variable was amount of time playing. The independent variables were disability status of the child (no disability, physical disability, or mental disability) and the gender of the parent (male or female). After collecting data, the researcher ran a Two-way ANOVA. According to the following SPSS output, how would you describe the interaction effect between disability status and gender?  

An investigator is studying the effect of a new growth hormo…

An investigator is studying the effect of a new growth hormone injection on height of school aged boys with short stature. He has the boys come into the clinic every 6 months to have their height measured precisely on a calibrated stadiometer. What is the dependent variable?