The best answer to the question: The focus of this study is MOST accurately defined as:___, would be: Insomnia.
Explanation:
This scientist wishes to investigate the effects of failure of sleep on athletic performance. However, the characteristics of the people he is seeking to form part of his research sample group are very unique in that all of them have had loss of sleep, be it complete, or partial, but it does not matter the reasons as to why these people were unable to sleep. So, most likely what this researcher is looking for is simply to define the effects of insomnia, which is simply defined as the inability of a person to get enough sleep, regardless of causation.
