Question

One tank of goldfish is fed the normal amount of food once a day; a second tank is fed twice a day. A third tank is fed four times a day. The fish’s weight is recorded daily.

what is the independent variable, dependent variable, control, constants?

Answer 1

The independent variable is the element or detail of the experiment which is changed between the groups or trials. In this experiment, where they change the amount of food given to the fish, what would the independent variable be?

The dependent variable is the element or detail that is expected to change as a result of the independent variable changing. Think about your answer for the "independent variable"; what will this affect? Given that the weight of the fish is being recorded in response to changing amounts of food, what would be the dependent variable?

The control is a group that experimenters use as a baseline. You could think of it as the default state, where no changes are made to the "independent variable". Which of the groups (normal amount of food, double amount of food, 4 times amount of food) would be the control?

Constants are any aspects of the experiment which are not changed between the experimental groups. Although they are not specified in the experimental design, examples of constants could include the type of food used, the type of fish being fed, the size of the tank, the conditions of the tank water, etc...

I hope this quick rundown helps you to identify the parts of this experiment (as well as any experiments you might encounter later on)!

Answer 2

thx

Answer 3

Not a problem :)