The study found an association between screen time and language delay in a sample of 900 18-month olds. Photo: Maria Sbytova/Shutterstock
This CNN story reports on research presented at an academic conference for Pediatrics. According to the conference presentation,
[A] study found that the more time children between the ages of six months and two years spent using handheld screens such as smartphones, tablets and electronic games, the more likely they were to experience speech delays.
According to this description, the two main conceptual variables in the study are "time spent using a handheld screen" and "speech delay." Read on to find out how each variable was operationalized:
In the study, which involved nearly 900 children, parents reported the amount of time their children spent using screens in minutes per day at age 18 months. Researchers then used an infant toddler checklist, a validated screening tool, to assess the children's language development also at 18 months. They looked at a range of things, including whether the child uses sounds or words to get attention or help and puts words together, and how many words the child uses.
a) According to the text, how did the study operationalize the variable, time spent using a handheld screen? Do you think this was a valid measure? Why or why not?
b) According to the text, how did the study operationalize the variable, speech delay?
c) The passage describes the infant toddler checklist as "a validated screening tool"--how do you think this tool was validated? What data might they have collected to validate this measure? (apply concepts from Chapter 5)
d) Sketch a scatterplot of the association they reported in the first quoted section.
e) Does this association allow us to conclude that "exposure to handheld screens causes children to experience speech delays?" Why or why not?
Read the following description; identify the mediator that the speaker is proposing.
"We do know that young kids learn language best through interaction and engagement with other people, and we also know that children who hear less language in their homes have lower vocabularies." It may be the case that the more young children are engaged in screen time, then the less time they have to engage with caretakers, parents and siblings, said [an expert who commented on the findings].
f) Sketch the mediator pattern that is hypothesized above.
Suggested answers
a) This variable appears to have been operationalized via parents' reports of their children's screen time.
b) Speech delay may have been operationalized with multiple measures. It is not clear from the reporting if the Infant Toddler Checklist is one measure, separate from whether the "child uses sounds or words to get attention or help and puts words together, and how many words the child uses," or if these three components comprise the infant toddler checklist.
c) One way to validate a measure such as the Infant Toddler Checklist would be through a known groups paradigm. Professional speech language pathologists might identify groups of children who either do have speech delay or do not. Then all children in the two groups would be administered the Checklist. If the Checklist is valid, then the group who have been diagnosed with speech delay should score lower on it than the group who who have been diagnosed as developing normally.
d) Your scatterplot should have "Speech delay" (or, alternatively, "Infant Toddler Checklist") on one axis and "Time spent on screens" on the other axis. The dots should slope upwards from left to right.
e) The results show covariance: Speech delay is associated with time on screens. The method does not allow us to establish temporal precedence, since both variables were apparently measured at the same time. We do not therefore know if the screen time came first (inhibiting speech delay) or if children with speech delays are more likely to be drawn to screens (perhaps to cope with frustration of not communicating easily). Internal validity also is not established. A reasonable third variable explanation might be time in day care: it is possible that children in day care are both less likely to be on screens (because most day cares have lots of other toys) and children in day care are exposed to more language because there are more people around.
f) You'd draw this mediator pattern:
exposure to screens ---> less social engagement with caretakers ---> language delay
