Question

The article "Television's Value to Kids: It's All in How They Use It" (Seattle Times, July 6,2005 ) described a study in which researchers analyzed standardized test results and television viewing habits of 1700 children. They found that children who averaged more than two hours of television viewing per day when they were younger than 3 tended to score lower on measures of reading ability and short term memory. a. Is the study described an observational study or an experiment? b. Is it reasonable to conclude that watching two or more hours of television is the cause of lower reading scores? Explain.

Short answer

a. The study described is an observational study. b. It is not reasonable to conclude that watching two or more hours of television is the cause of lower reading scores based solely on the evidence presented in this study.

Step-by-step solution

Identify the Type of Study

Consider the characteristics of the study described. An observational study involves observing and measuring variables without influencing them. An experiment, on the other hand, involves applying some treatment or condition to one group while having a control group for comparison. In this study, the researchers did not manipulate the viewing habits of the children; they merely collected data on their habits and their corresponding test results, making it an observational study.

Understand Correlation Versus Causation

Grasp the concept of correlation and causation. Two variables may be correlated without one necessarily causing the other. For example, a correlation might exist between the amount of ice cream sold and the number of drownings on a certain day, but it would be wrong to say that ice cream causes drownings. An external factor like high temperatures could cause both to rise. Simply demonstrating that two variables are correlated does not prove causation. Causation implies a cause-and-effect relationship that can only be demonstrated under controlled experimental conditions.

Apply Understanding to This Study

Now apply these principles to relationships between television viewing and reading scores. The study found a correlation between children who watch more than two hours of television a day before age three and lower reading ability and short-term memory. However, the study did not manipulate the amount of TV watching to demonstrate a causal link. Therefore, it is not reasonable to conclude solely based on this study that watching two or more hours of television is the cause of lower reading scores. Other variables, like parenting, socio-economic status, or individual child differences, could also influence both TV watching and reading ability.