The hardest part of quantitative market research is not that it involves numbers, math, or even statistics, but that it involves complex problems in probability. Over the past several years, psychologists have been documenting how difficult it is for us humans to solve even “simple” probability problems. One fascinating example is a puzzle known as…
The most recent government estimates of cell phone usage among U.S. households were released a few weeks back, and the pace at which landline usage is disappearing is astonishing. Here are just some of the numbers: Thirty percent of U.S. households do not have a landline telephone An additional 16% have a landline telephone, but…
These days most researchers agree that if you want to do a random sample phone survey of the U.S. population, you ought to include cell phones. More than one-quarter of the population do not have landline telephones at home. Those who do have landline telephones are less likely than ever to answer them, and less…
A good chart is the best way to understand the law of diminishing returns when it comes to sample size. So for our June 2011 newsletter we built an interactive graph for choosing sample size. It’s cool, educational, and useful. Moreover, it will show you just how mind boggling the numbers behind sampling can be. …
A new study presented by two professors from Harvard University and the University of Massachusetts at Amherst was probably one of the liveliest and potentially disruptive presentations at least week’s annual meeting of the American Association of Public Opinion Research (AAPOR) in Phoenix. Why? Because their research challenges the beliefs of many AAPOR-ites who disregard…
The latest data from the CDC’s National Health Interview Survey show that one quarter (25%) of U.S. adults do not have land-line telephones in their homes. So if you conduct a traditional random-digit-dial (RDD) phone survey, you will automatically be excluding one quarter of the population. Does it matter, given that surveys rarely interview everyone…
With the magic of the holidays upon us, we got to thinking about “magic” in market research, or the lack thereof. So our just- published quarterly newsletter focuses on magic numbers in market research, arguing that certain “magical” numbers seem to guide much of what we do, whether we realize it or not. The best…
The idea of sampling is not hard to grasp, but methodological discussions about sampling can quickly move into the higher reaches of mathematics and probability that confuse even researchers who are not statisticians. Ever wonder what we are talking about when we refer to “probability samples?” Or the rationale for not reporting margins of error? …
Many assume that rigorous market research always works with random samples or probability samples. This assumption is not true. There are many studies that require purposive sampling instead. Purposive sampling involves finding people with specific characteristics or qualities, even if they do not fully represent the whole population, because these specific people can provide unique…
Should you state a survey’s margin of error in your press release when pitching a story to the media? In our view, the answer is no. Why not? Because margins of error refer to sampling error only, not about the overall accuracy or error of the survey itself. But how many readers of your news…