experiments (1 Viewer)

[kony]

hi, could someone please clarify these for me.

1. what is a "control" in an experiment. (i'm thinking this is either the variable we change or a quantity that is not changed such as the angle of rotation in the pendulum experiment)

2. what constitutes a "fair test"?

3. any additional tips for pracs in general?

 

[jest3r]

Ahoy hoy,

I'd recommend having a read through this website http://www.sciencebuddies.org/mentoring/project_variables.shtml

Constituting a "fair test", I would probably say that basically, and one of the most important things that my teachers seem to stress is duplicating the experiment. In class, this will probably be done by carrying out an experiment in groups. Essentially, this increases the reliability of the results obtained. Another factor would also be making sure that the conditions, other than the variable being tested, are kept constant in each experiment. Using a very simple example, say if you were carrying out an experiment to test if certain additives in solutions cause a change in the rate of growth of pea plants, to make the test as fair as possible, you would, ofcourse, use the same type of pea plant, add the same amount of solution to each seed, situate all of the seeds in the same area etc.

As for additional tips for pracs in general, I guess you should consider the dependent and independent variables and always consider safety precautions. The later apparently constitutes a lot of hsc exam questions based around mandatory pracs. Anyway, hope this has helped.

 

[alcalder]

One place to bookmark and refer to often is this palce:

http://webs.mn.catholic.edu.au/physics/emery/accuracy.htm

Always remember, accuracy, reliability and validity.