Consider the following studies:
Study 1: A study was conducted to investigate the effects ofalcohol consumption on handeye
co-ordination. 200 people were interviewed and their level ofalcohol consumption
over the previous five years was assessed and classified as eitherlow, medium or high.
Each person was then given a series of tasks resulting in ahand-eye co-ordination score.

Study 2: A study was conducted to investigate the efficacy of a newiron tablet compared to a
currently used iron tablet. It is known that the level of efficacyfor iron tablets is different
for males and females. 200 people were available for the study.First, they were divided
into males and females. Then these two groups were randomly splitin half – one half was
given the new tablet, while the other half was given the existingtablet. At the start of the
study, all participants were given blood tests and their ironlevels measured. After six
weeks of taking the iron tablets, they were given another bloodtest and their iron levels
measured again. For each subject, the difference in iron levels wasrecorded. The average
of the differences were then compared separately for males andfemales.

(a) Answer the following questions FOR EACH study:
(i) Identify the groups that are being compared. (I.e., whattreatments or factors of interest
are being compared?) DO NOT also say what is being measured to makethe
comparison – you do this in (ii).
(ii) What is being measured to compare these groups? ONLY describethe variable being
measured. DO NOT also mention the groups being compared – you dothis in (i).
(iii) Would you describe the study as an experiment or anobservational study?
- If it was an experiment, what part of the study design led you tothis conclusion?
- If it was an observational study, could an experiment have beeneasily carried out
instead? If so, briefly explain how. If not, briefly explain whynot