3 PROFESSORS WANT TO KNOW IF HAVING 500 STUDENTS IN THEIR CLASS IS DETRIMENTAL TO PROPER LEARNING. 1ST PROFFESSOR RANDOMLY HANDS OUT THE QUESTIONNAIRE TO 50 STUDENTS; ALL 50 ARE RETURNED TO HIM DURING CLASS. 2ND PROFFESSOR HANDS OUT THE QUESTIONNAIRE TO ALL 500 STUDENTS AND ONLY 100 RETURN THEM AT THE END OF CLASS. 3RD PROFESSOR REFEERS HIS 500 STUDENTS TO A WEBSITE FOR THE QUESTIONNAIRE AND 100 OF THEM RESPOND. WHICH PROFESSOR HAD THE BEST WAY OF DOING HIS SURVEY? WHICH ONE WAS THE WORST?

2 answers

Thank you for using the Jiskha Homework Help Forum. In the future, please do not use CAPITAL letters as it is considered impolite (like shouting) and is harder to read.

Did the first professor only have 50 in the class? If so, he may have wasted class time filling out the questionnaire, but he got 100% results. If the 2nd has 500 students in a class, it's a wonder anyone learns anything! He only had 20% response. The 3rd professor wasted no time in class but who knows how many will even go to the Website.
The first one who hands out survey randomly to 50 of the 500 students is the best. There will be minimal bias.

The website survey is the worst, because it will be biased by those who chose to respond and those who have computers available. This is why political surveys are no longer done by telephone.

Of the 100 of 500 who returned the handed-out questionnaire, there may be some bias within the group responding. Previously, some surveys that were not done randomly concluded that their population was very polarized — either extremely pro or extremely con — in terms of the topic. However, they did not realize that those in the middle — who did not care one way or the other or did not have strong feelings about the topic — would be very unlikely to fill out and return the questionnaire.

I hope this helps a little more. Thanks for asking.