Encourage Kids to Read!Researchers1asked parents of 19 American children, ages 8 to 12, to complete surveys on the number of hours their children spent reading and on the number of hours they spent on screen-based media time. Each of the children also underwent magnetic resonance imaging to assess connectivity in the brain. More time spent reading was associated with higher connectivity,while more screen time was associated with lower connectivity in the brains of the children.

1. Horowitz-Kraus T and Hutton J, "Brain connectivity in children is increased by the time they spend reading books and decreased by the length of exposure to screen-based media,"Acta Paediatrica, 107, 2018.

How many cases are there in this study?

How many variables are there?

Identify each of the variables as quantitative or categorical. Also, identify each of the variables as an explanatory variable or a response variable.

Hours spent reading:

categorical

quantitative

explanatory

response

Hours of screen time:

categorical

quantitative

explanatory

response

Connectivity in the brain:

quantitative

categorical

explanatory

response

Is this an experiment or an observational study?

Observational Study

Experiment

Can we conclude that more time spent reading increases connectivity in children's brains?

Yes

No

Which of the following is likely to be a confounding variable in this situation?

Parents who encourage reading and discourage screen time are likely to provide more mental stimulation in general to their kids than do other parents

Reading increases brain connectivity in children

Children who read a lot generally have less screen time

Screen time decreases brain connectivity in children