Suppose you are conducting a study to compare firefly populations exposed to normal daylight/darkness conditions with firefly populations exposed to continuous light (24 hours a day). You set up two firefly colonies in a laboratory environment. The two colonies are identical except that one colony is exposed to normal daylight/darkness conditions and the other is exposed to continuous light. Each colony is populated with the same number of mature fireflies. After 72 hours, you count the number of living fireflies in each colony.

(a) Is this an experiment or an observation study? Explain.

This is an observational study because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

This is an experiment because observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured.

This is an experiment because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

This is an observational study because a treatment was deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured.

(b) Is there a control group?

No, there is no control group in this study.Yes, the control group has light 24 hours per day.Yes, the control group receives normal daylight/darkness conditions.Yes, the control group is kept in the laboratory.

Is there a treatment group?

Yes, the treatment group has light 24 hours per day.Yes, the treatment group receives normal daylight/darkness conditions.Yes, the treatment group is kept in the laboratory.No, there is no treatment group in this study.

(c) What is the variable in this study?

the number of fireflies living at the end of 24 hoursthe amount of daylight the fireflies receivethe way the fireflies react to differing light conditionsthe number of fireflies living at the end of 72 hours

(d) What is the level of measurement (nominal, interval, ordinal, or ratio) of the variable?

ratioordinalintervalnominal