Here's another example of a research summary from The Conversation, which invites researchers to produce accessibly-written summaries of their own research.
This one concerns a study that conducted a randomized controlled trial of interventions for kids at-risk for obesity. Here's how the researchers, Amanda Harrist and Laura Hubbs-Tait, described their research:
We conducted a randomized controlled trial in 29 Oklahoma schools. More than 500 first graders who were at-risk for obesity – meaning their BMI was above the 75th percentile – were assigned to either a control group or a group that received a combination of three interventions.
These interventions focused on family lifestyle, family dynamics and the peer group.The family lifestyle intervention focused on healthy food and physical activity. ....
The family dynamics intervention added parenting skills and healthy emotion management.
The peer group intervention taught social acceptance in the children’s school classrooms, ... teaching children to be more accepting of one another.
(note: please read the post for full details about these three parts of the intervention)
Here are the study's results:
We measured children’s heights and weights at the beginning of first grade and then after the intervention – in first, second, third and fourth grades. Only those children with obesity who received the three interventions – family lifestyle, family dynamics and peer group – had significant decreases in BMI gains compared with the control group.
Questions
a) The authors call this a "randomized controlled trial", so that should tell you they conducted an experiment. What was this study's independent variable (IV) and what were its levels?
b) Was the IV manipulated as independent-groups or within-groups?
c) What was this study's dependent variable?
d) Which of the four simple experimental designs does this seem to be--posttest only? Pretest-posttest? Concurrent measures? or Repeated measures? Explain your answer.
e) Sketch a graph of the study's results, labeling your axes mindfully.
f) In this study, the researchers randomly assigned schools to the different conditions, rather than individual children. Why do you think they might have done it this way?
The researchers' summary in The Conversation focuses on two conditions (control condition and an intervention that combined three elements). But the full study actually contained more than two conditions. You can read the full study here (open access): https://www.mdpi.com/1660-4601/18/16/8744
