Acidus wrote:

In 1998, traffic accidents caused 46 percent of all accidental deaths of infants
and children aged 1 to 14 (National Center for Health Statistics, 2000). One
study (Johnston et al. 1994) showed that the single strongest risk factor for injury in a traffic accident is the improper use of child-safety seats. Another study (Kahane 1986) showed that, when correctly used, child safety seats reduce the risk of fatal injury by 71 percent and hospitalization by 67 percent.

To be effective, however, the seats must be installed correctly. Other studies,
showed that 79 to 94 percent of car seats are used improperly (National Highway
Traffic Safety Administration 1996, Decina and Knoebel 1997, Lane et al. 2000). Public-health specialists Dr. Mark Wegner and Deborah Girasek (2003) suspected that poor comprehension of the installation instructions might contribute to this problem. They looked into the readability of the instructions and published their findings in the medical journal Pediatrics. The story was covered widely in the media.

The authors referred to the National Adult Literacy Study (National Center for
Educational Statistics, 1993), which states the average adult in the U.S. reads at the 7th grade level. They also cited experts in health literacy who recommend that materials for the public be written at the fifth or sixth-grade reading level (Doak et al., 1996; Weiss and Coyne, 1997).
Their study found that the average reading level of the 107 instructions they
examined was the 10th grade, too difficult for 80 percent adult readers in the U.S.

Read world implications for readability computations is sexy.

Why should you need to read at a '10th grade level' to understand instructions? You shouldn't even HAVE to read to use good product instructions. They've got it all wrong.