Question

Identify which goal of experimental design (i.e., reducing bias or limiting effects of sampling error) is aided by the following procedures below:
a) Including extreme treatment levels?
b) Using a paired design?
c) Keeping room temperature constant in an experiment designed to test the effects of a pesticide on insect survival?
d) Eliminating artifacts when designing the treatment of interest?
e) Adding a sham operation group?

For each choice, mark off if it reduced bias or if it reduced sampling error.

Thanks you!

Answer 1

ANSWER:

GIVE THAT

• Here we have to choose the process by which we can control sampling error To reduce bias or limiting effects of sampling error.
• Sampling errors are the errors which can be controlled by a systematic experimental designing .In given option ,

Option (c) is correct option.

• Because in option (a), statement says about including extreme treatment levels , but it is not useful for reducing partiality  or sampling error .
• it is not suitable to take extreme treatment level in any experiment .
• In option (b) , if we use paired design then by comparing results from two paired experiments

we can identify the efficiency of model we used it cannot reduce bias .

• Option (c) , to test effect of pesticides on insect , we have to assume that all other variables are constant in all process and only main variable ( pesticide) affect insect survival ,because temperature can also affect survival of insects. So we have to control temperature throughout the process to reduce partiality in result.
• similarly option (d) and (e) are not useful for reducing sampling error .

Hence option (c) is correct .