Question

EXERCISE 3: EXPERIMENTAL VARIABLES

Identify the variables tested in each of the following experiments. If applicable, determine and identify any positive or negative controls.

1. A study is being done to test the effects of habitat space on the survival of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment the number of surviving fish are surveyed.

a. Independent Variable:

b. Dependent Variable:

c. Controls:

Answer 1

Independent variable is those variable whose variation dies not depend on other factir . It is independent in nature.

Dependent variable is that variable whose variation depends on other factors. Based on this information we can easily answer the above questions.

1) here independent variable is different habitate space used in the experiment.

As this factor is independent , not dependent on other factor .

2) dependent factor is survival of fish .

This factor is dependent on , different habitat space used in experiment.  

3) control is survival of fish in natural habitat. So  survival in natural habitat will be considered as 100%. And effect of different habitat space on fish survival will be will be calculated as compared to control.