Whether or not to continue a Mardi Gras Parade through downtown San Luis Obispo, CA, is a hotly debated topic. The parade is popular with students and many residents, but some celebrations have led to complaints and a call to eliminate the parade. The local newspaper conducted online and telephone surveys of its readers and was surprised by the results. The survey web site received more than 400 responses, with more than 60% favoring continuing the parade, while the telephone response line received more than 100 calls, with more than 90% favoring banning the parade.

What factors may have contributed to these very different results?

1) The size of samples is too small to avoid chance variation.

2) Different subpopulations used the website and the telephone.

3) People were forced to lie about their preferences.

4) People waver between two opinions.