Final answer:
To determine the number of subjects in an experiment, guidelines from statistical literature, ethical considerations, and practical constraints are considered. The use of control groups, randomization, and sufficient sample sizes are essential for reliable results.
Step-by-step explanation:
To determine the number of subjects to use in an experiment, several guidelines are considered. One key aspect is the statistical literature, which offers rules of thumb on sufficient sample sizes based on assumptions about the distribution of observations and past experiences from similar studies. A common experimental design tactic is to divide subjects into different groups and have at least one group serve as a control group for the accurate assessment of the treatment effect.
Randomization plays a crucial role in assignment to treatment groups to eliminate bias and lurking variables. Additionally, ethical considerations must be taken into account to conform to the scientific community's expectations of responsible research. Sample sizes can vary greatly depending on the nature of the experiment and the expected variability of the data but should be large enough to offer reliable insights while considering practical constraints.