Average privacy policy takes 10 minutes to read, research finds

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Website privacy policies take on average 10 minutes to read and sometimes run into thousands of words, researchers have found. While some are short, others would take over half an hour to read, researchers said.

Researchers Aleecia McDonald and Lorrie Faith Cranor of Carnegie Mellon University looked at online privacy policies and how long it would take to read them. While one policy they looked at was just 144 words long, they found one policy on a popular site that ran to 7,669 words, around 15 pages of text.

The average length of privacy policies used by the 75 most popular US websites is 2,500 words, the research found. Using the reading speed of 250 words per minute which is typical for those who have completed secondary education, the average policy would take 10 minutes to read.

The length of privacy policies is often cited as one reason they are so commonly ignored. "Studies show privacy policies are hard to read, read infrequently, and do not support rational decision making," said the researchers, acknowledging the fact that the policies are rarely read.

The researchers also investigated how quickly people could read privacy policies when they were just skimming it for pertinent details. They timed 93 people as they skimmed a 934-word privacy policy and answered multiple choice questions on its content.

Though some people took under a minute and others up to 42 minutes, the bulk of the subjects of the research took between three and six minutes to skim the policy, which itself was just over a third of the size of the average policy.

The researchers used their data to estimate how much it costs US citizens to read the privacy policy of every site they visit once a year if their time was charged for. Were people to actually read the policies and charge for that time it would cost $652 billion a year.

Though that figure has limited usefulness, because people rarely read whole policies and cannot charge anyone for the time it takes to do this, the researchers concluded that readers who do conduct a cost-benefit analysis might decide not to read any policies.

"Preliminary work from a small pilot study in our laboratory revealed that some Internet users believe their only serious risk online is they may lose up to $50 if their credit card information is stolen. For people who think that is their primary risk, our point estimates show the value of their time to read policies far exceeds this risk. Even for our lower bound estimates of the value of time, it is not worth reading privacy policies though it may be worth skimming them," said the research.