Points..points, What type of sample is explained below and what are the disadvantages of this type of sample?

Question

A Lecturer decides to interview a sample of 10% of students and considers several ways of selecting the sample. One method is to interview the 1st 24 students to arrive at the next lecture.

Answer 1

I would call it a biased sample; but it could be deliberate, in as much as the Lecturer may want to examine the particular characteristics of early arrivers. Of course, in your question you don't explain what the lecturer is trying to achieve, and why he has selected a sample of 10%. If he truly wants an unbiased sample, then selecting the first 24 (total 240 not 140 as stated above) then he is in danger of selecting students from early arrivers who share other characteristics associated with enthusiasm.

Answer 2

Since the interview is to be conducted on a sample of students, chances are, he/she is trying to infer something about the whole frame of students.

Interviewing the 1st 24 students assumes the order in which they arrive for the lecture is random, in that there is no common characteristic in these first 24, or that characteristic has nothing to do with what the lecturer is trying to infer.

Chances are, this will not be the case and the sample will be biased. Students who tend to arrive the first at lectures tend to be the same people all the time and tend to be similar to each other (and different from others).

So the inferences are likely to be biased and it will not be appropriate to apply them to the whole population of students.

A simple way to remedy that would be to interview every 24th student rather than the first 24: 1, 25, 49... ...

Answer 3

If he's to interview 10% then that means there must be 124 people in the class. However if he interviews the first 24 students to arrive then he hasn't taken an overall 10% of the class. By interviewing the first 24 to arrive he's only getting the views of probably the nerdiest students. He should therefore take a percentage from the first to arrive, the middle lot to arrive and the last to arrive. That way you should get an overall 10 % of the sample.

Answer 4

This could be known as a convenience sample -- a nonprobability sample, therefore no generalizations can be made to the population at large from which it comes. The likelihood that the first 24 students to arrive at the lecture would have significantly different characteristics from the average student is high, thus sampling error is high.

Answer 5

these students turn up on time or early. you're aren't sampling the lazy bums who are hung over and still in bed!

Answer 6

you'll get some like this: placed an & signal formerly and a ; after each and each abbreviation ? is radic ± is plusmn ? is le ? is ge ? is pi ° is deg ? is asymp or play round with alt then a huge decision then enable bypass: listed decrease than are some ?²? ??????•????????????¶§????????????????

Answer 7

too small; not random