<span>The threat to internal validity is the Mortality. Internal
validity is the measure in which the causality of the stimuli studied
is analyzed, that is, if the results of the study are due to the
interaction of the variables analyzed or are due to the interaction with
other variables. <span>Mortality is an error that occurs if the
conclusions of the study are made only on the basis of the participants
who were from beginning to end in the investigation, without taking into
account those who left the study.
I hope my answer can help you.
</span></span>
Answer:
U.S. Department of Labor
Explanation:
Weekly jobless claim statistics are published by the Employment and Training Administration (ETA) of the US Department of Labor. The agency was given its current name in 1975. It maintains a web site making available statistics since 1967.
Answer:
This is an example of: <u>a sample survey.</u>
Explanation:
In the experiment to determine the effect of sleep deprivation on the ability of the student to concentrate definitely needs an experimental setup rather than a randomized data collection.
<em>Do to the fact that, the experimental used a small sample sized area (Students in a calculus class) to test his hypothesis shows that the setup is a sample survey. </em>
<u>This sample survey result could be extrapolated to the whoe region (the classes in the school or whole school ) to determine if there was a major significance between the two variables.</u>