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# Sampling methods and level of measurements

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1) American On Line ran a poll of its Internet subscribers and asked this question - Should the World Trade Center towers be rebuild?" among the 1,304.240 response : 768, 731 said Yes and 286, 756 answered NO and 248,753 said that they were "undecided". Being that this sample is extremely large can the responses be considered to be representative of the population of the United States?

2) Visa wants to conduct a survey of credit card usage among the full-time students who attend college. What is a good procedure for obtaining a sample of each type: random, systemic, convenience stratified, cluster.

3) a) the weights of people in a sample of elevator passengers
b) a movie critic's ratings of "must see; recommended; not recommend; don't even think about going"
c) a movie critic's classification of "drama, comedy, adventure"
d) Bob, who is different in many ways measures time in days, with 0 corresponding to his birth date. The day before his birth is -1 , the day after his birth is +1 and so on . Bob has converted the dates of major historical events to his numbering system. What is the level of measurement of these numbers.

IDENTIFY WHICH OF THE ABOVE IS Nominal, Ordinal, Interval, Ratio level of management.

https://brainmass.com/physics/scales/sampling-methods-and-level-of-measurements-110733

#### Solution Preview

There are a number of limitations associated with study. The foremost of which is the lack representativeness of the sample. The sample selected is not random. Only subscribes of American Online can participate in this study. Randomness is the fundamental principle of any statistical study.

The Internet population has a slight bias towards younger, more computer literate users. The study limited the potential pool of respondents to those already involved in online activities and some members of the target population may have not participated because of their discomfort with on line interactions.

Thus in the above study sampling error is not controlled. It can be noted that the sampling error tend to increase with increasing sample size. Thus sample collected is not a representative of the population of the United States.

Reference

1. Hamilton, J. C. (1999). The ethics of conducting social science research on the Internet. The Chronicle of Higher Education, 46 (15), B6-7.
2. Stanton, J. M. (1998). An empirical assessment of data collection using the Internet. Personnel Psychology, 51 (3), 709-725.

2) Visa wants to conduct a survey of credit card usage among the full-time students who attend college. What is a good procedure for obtaining a sample of each type: random, systematic, convenience stratified, cluster?