Chapter 4.2, Problem 46E

(a)

To determine

To find: that this is an experiment or observational study, justify the answer.

Answer to Problem 46E

Observation study

Explanation of Solution

This was an observation study where an observer analysis collects information on the possible impact of a treatment about subjects where a subject is not monitored by the researcher when assigned to a treated group vs a control group. The researchers have actually tracked them into their sixth school year and asked adults to assess their behaviour.

(b)

To determine

To find: the response and explanatory variables.

Explanation of Solution

Since time is spent in childcare between 4 and a half of age, adult ratings can be clarified. In childcare the explanatory variable from birth to the age of four and a half was the amount of time. Adult assessments of their behaviour have become the response variable.

(c)

To determine

To explain: this research reveals that childcare is violent for children.

Answer to Problem 46E

No, there is chance lurking variable.

Explanation of Solution

No. This research cannot suggest that childcare makes kids more violent because the analysis is an observational analysis and it cannot infer cause and effect; a mysterious variable may exist which directly causes their actions to vary in adult ratings.