Take a look why it is a joke poll:
Among all Badger state residents: Feingold 25%, Johnson 19% (N=500)
Among registered voters: Feingold 27%, Johnson 21% (N=466)
Among likely voters: Feingold 33%, Johnson 28% (N=297)
Results shown here are based on 500 persons who were randomly chosen within households with working landline telephone numbers and interviewed between June 9th and July 10th, 2010, inclusive. During this time period, the UWSC made 12,889 phone calls to 2,245 telephone numbers. Additionally, advance letters describing the survey and its procedures were sent to 800 households whose randomly chosen telephone numbers were matched to a known listed address. The response rate for this survey was 38.2%, as defined by the American Association of Public Opinion Research Response Rate 3. Calls were made between 9AM and 9PM Monday through Friday and between 10AM and 5PM on Saturday and from 12 noon to 9PM on Sunday. All telephone numbers were randomly generated by computer. The UWSC made up to 10 attempts on each number in order to confirm if it was a residential number, select an eligible respondent and/or to convert first time refusals. Approximately 51% of the 500 interviews were completed in the first two weeks of calling.
Theoretically, results from this survey have a "margin of error" of a little over +/- 4%.
http://www.uwsc.wisc.edu/BP30PressRelease2_SenRace.pdf
