An Essential Report poll finding that 49% of Australians want to ban Muslim immigration received extensive media coverage last week.
Senior journalists and politicians took the findings at face value.
Some aspects of the Essential findings are worthy of critical scrutiny. One relates to methodology.
There are two main approaches to surveying. One is a sampling of the population based on randomly generated telephone numbers. The other utilises an online panel of respondents who complete surveys out of interest and for reward.
Surveys employing online panels are much cheaper and quicker to run. They have a proven record on a number of issues, notably predicting election outcomes, as over a period of years they develop weighting formulas for their panel calibrated against election results. But there are no formulas of the same level of precision when surveys deal with social issues.
