Final answer:
It is true that controlling all variables in a scientific experiment, such as a medical trial (MT), is difficult due to the complexity involved. Ensuring large sample sizes can help in obtaining more reliable outcomes. While experiments allow for cause-and-effect analysis, they also have limitations and challenges, including ethical considerations when conducted on humans.
Step-by-step explanation:
It is true that it is difficult to control all the variables of a MT session for the purpose of attaining measurable outcomes. In scientific experiments, it is often challenging to control all variables, especially when dealing with complex systems like the human body or environmental factors. While careful design and methodology can help manage many variables, it is impossible to achieve complete control over every factor.
Larger sample sizes are generally better than smaller ones in scientific experiments because they can help reduce the impact of outliers and provide more reliable data. This is true because larger sample sizes increase the likelihood that the sample accurately represents the population, allowing for more definitive conclusions.
When it comes to making cause-and-effect claims, experiments must be carefully designed to control for as many confounding variables as possible. However, it is true that experiments, including those involving humans, do come with ethical, practical, and technical challenges that can sometimes limit the ability to fully manage all variables.