The independent variable is the amount of water consumed by the football players.
The dependent variable is the football players' endurance, measured by how many times they can run up and down the bleachers before catching their breaths.
The coach's hypothesis was that the more water consumed, the more endurance the players will have.
There is not a control group present in this experiment, but it would be the set of players who did not drink a bottle of water before practice.
The experimental group is the set of players who did drink a bottle of water before practice.
The constants in the experiment are the operational definitions of endurance (how he measures their endurance), the amount of water each player drinks throughout the week, and the players used in the experiment.
The lack of a set control group poses a threat to the accuracy of the experiment's results.
Answer:
A Scientific experiment is designed in such a way that it should test the hypothesis.
The experiments contain three types of variables: independent variable-which can be manipulated, dependent variable- which has to be tested and the constant- which is kept constant throughout the experiment.
The scientific experiment can be categorized into two samples: the experimental group in which the dependent variable is tested and the control group in which the dependent variable is not present.
Therefore in the given question
1. independent variable- the amount of water which was changed throughout the experiment.
2. dependent variable- the endurance power measured.
3. hypothesis- If more water is consumed, then more endurance is observed in athletes.
4. Control group- No control group was included in the experiment.
5. Experimental group- the groups who drank water before practice
6. Constant- the number of players and water consumed per week.
7. The problem is that it lacked the reference group or control group which will provide the data to compare with.
