The answer is: his study does not qualify as an experiment. For the study to be an experiment, Dr. Kline would have to manipulate the independent variable in a group (for example, apply a certain treatment) and also have a control group to which he doesn’t apply such treatment.
In this case, the study is an observational study because he only observed the subjects that were in the zoo that morning and measured the variable of his interest, that is the environmental attitude of the visitors, he did not apply a certain treatment to the group nor manipulate any variable.
Explanation:
it control my values my acts my point of view my thought . it influence me in every thing
2.) is Mexico City and 3.) is floating