How readable are child safety seat installation instructions?

Pediatrics. 2003 Mar;111(3):588-91. doi: 10.1542/peds.111.3.588.


Objectives: To measure the required reading level of a sample of child safety seat (CSS) installation instructions and to compare readability levels among different prices of CSSs to determine whether the lower cost seats to which low-income parents have greater access are written to a lower level of education.

Methods: A CD-ROM containing CSS installation instructions was obtained from the National Highway Traffic Safety Administration. Pricing information was obtained for available models from an Internet-based company that provides comparative shopping information. Paper copies of the instruction sets were generated, and their readability levels were determined using the SMOG test. A second rater was used in addition to the primary investigator to assess interrater reliability of the SMOG as applied to the instruction sets.

Results: The readability of instruction sets ranged from the 7th- to 12th-grade levels, with an overall mean SMOG score of 10.34. No significant associations were found to exist between readability and seat prices; this was observed whether the data were treated as continuous or categorical.

Conclusions: CSS instruction manuals are written at a reading level that exceeds the reading skills of most American consumers. These instruction sets should be rewritten at a lower reading level to encourage the proper installation of CSSs.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Child
  • Comprehension*
  • Costs and Cost Analysis / statistics & numerical data
  • Educational Status*
  • Female
  • Humans
  • Infant Equipment / economics
  • Infant Equipment / statistics & numerical data*
  • Male
  • Pamphlets*
  • Parents / education*
  • Parents / psychology