The researchers studied 1013 children aged ten to eleven years old and they came from 23 primary schools in the Bristol England school district. They were part of a program called the Personal and Environmental Associations with Children’s Health Project that was conducted between September 2006 and July 2008. To participate in the study, parents had to give their consent. There were several measures that the researchers employed in order to understand each aspect of what they studied. The children were first measured by the amount of sedentary time they spent using an accelerometer. The children were told to wear the accelerometer while they were awake for seven days consecutively. They were to wear them on a belt around their waist for seven days. The accelerometers were programmed to record information (data) every ten seconds and then it was put into one-minute epochs. They defined sedentary time as "any minute in which <.100 counts were recorded" (p. 1012). Children were also asked to answer a computer questionnaire that answered the question, "How many hours a day do you usually spend playing on a computer (not for homework)" (p. 1012). Children reported between 0 and 5 hours each day.
In terms of physical activity, moderate/vigorous physical activity (MVPA) was used because of its history of being linked to psychological well-being. The researchers defined MVPA as "any minute in which >.2000 accelerometer counts were recorded" (p. 1012). The last measure was for psychological difficulties and these were measured through the use of a self-report instrument called the Strengths and Difficulties Questionnaire (SDQ) because it is a well-known inventory that tests psychological well-being in children. There were 25 items that children responded to, measured on a three-point scale and scored from 0 to 2.