Final answer:
The survey conducted by Mr. Hall on school skipping may face selection and social desirability biases, which can affect its accuracy and representativeness.
Step-by-step explanation:
When Mr. Hall surveyed fifty high school students asking them if they have ever skipped school, he may have introduced a potential selection bias or social desirability bias into his research. If the students were randomly selected and feel comfortable answering truthfully, the results may offer some insight into truancy rates. However, if there is a social pressure to respond in a certain way, or if the sampling method was not random, the results may not be representative of the true truancy rates. To answer the question properly, one should also consider other factors such as the time of day the survey was conducted, as it could influence who was available to participate. In survey research, it's important for the survey to be truly representative of the population of interest to draw accurate conclusions.