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Experiments and Variables - help5

Experiments are commonly performed in order to determine the effect of one variable (the independent variable) upon another variable (the dependent variable). When designing such an experiment, it is important to identify all possible variables that might effect the outcome on the dependent variable. Once done, hold all variables constant with the exception of the independent variable. Make systematic and controlled changes in the independent variable and measure the effect upon the dependent variable.

There are several versions of this question that differ only in terms of the randomized order of the answer options. Here is one of those versions:

Version 1:

A student lab group is brainstorming the design of an experiment in which they wish to determine how the frequency at which you shake a Slinky would affect the wavelength. Which Post-it note describes the most effective design?

Shake Slinky with frequency of 1.0 Hz. Measure the wavelength and the speed. Record data in notebook. Use a different speed and shake once more at 1.0 Hz. Measure and record the wavelength. Continue changing the wave speed while keeping frequency constant. Measure and record the wavelength for each trial.
Shake Slinky with frequency of 1.0 Hz. Measure and record the wavelength. Get a new Slinky and repeat the trial with a frequency of 1.0 Hz. Repeat for several different Slinkies, being careful to keep the frequency controlled at 1.0 Hz and measuring the wavelength in each trial.
Shake Slinky with frequency of 1.0 Hz. Then shake the Slinky with frequency of 2.0 Hz. Then shake with a frequencies of 3.0 Hz, 4.0 Hz, and 5.0 Hz. Record data for each frequency.
Shake Slinky with frequency of 1.0 Hz. Measure and record the wavelength. Shake Slinky at 2.0 Hz. Measure the wavelength. Repeat this procedure for 3.0 Hz, 4.0 Hz, and 5.0 Hz. Measure and record wavelength for each frequency.

You are going to have to do some reading here. As you read, make sense of the words. You are looking for a procedure that is going to allow one to determine the effect that changes in the frequency will have upon the wavelength. Such a procedure will be careful to keep everything constant and controlled except for the frequency. And from trial to trial, the wavelength will be measured.

Bad experimental designs will fail to control other variables besides the frequency or will fail to measure the wavelength. So read carefully and eliminate the poor designs and select out the design that isolates frequency as the independent variable and the only variable that is changed.

Sorry. We're pedaling as fast as we can but as of this writing we do not have any Tutorial information on the topic of experimentation and variables.