Assessing Suitability of Written Materials

There are many tools to assess the reading grade level of written materials. A readability test is a simple test technique for predicting the reading grade level required of the average reader in order to understand written materials. There are more than 40 different formulae that can be used to perform a readability test. The majority of formulas establish readability based on 2 factors:

  1. The number of difficult words (usually words with 3 or more syllables) in a sample — difficult words mean more syllables in the sample and a higher grade level.
  2. The average length of sentences — longer sentences with more words than in the average sentence translate to a higher grade level.

Readability formulas can be applied to prose-that is, running text-but not to tables, or word lists. Application of these two factors in a readability formula provides a grade-level rating. You can then compare the readability level of the materials with the reading skills of your patient population to determine suitability.

It should be noted that readability tests measure only the structural difficulty (e.g., vocabulary, sentence structure and idea density) of written text. They do not measure other factors related to readability, such as conceptual difficulty, organization of material, content, or reader characteristics.

The readability tests used most often are the Fry Readability Graph, Flesch-Kincaid Formula, and SMOG Formula.

Fry formula

The Fry Readability Formula (or Fry Readability Graph) is readability metric for English texts, developed by Dr. Edward Fry.

The grade reading level (or reading difficulty level) is calculated by the average number of sentences and syllables per hundred words. Except for very short pieces, 3 or more samples are selected and then averaged. The reason for selecting 3 samples is that the readability levels are often not uniform throughout the text. These averages are plotted onto a specific graph; the intersection of the average number of sentences and the average number of syllables determines the reading level of the content.

Fry formula has several advantages:

  • Is easy to use and takes only about 15 to 20 minutes to obtain results.
  • Uses reasonably small sample sizes (100 words), so it is suitable for both short and long documents.
  • Reveals which types of words and sentences are difficult.
  • Is not copyrighted.

To learn how to apply the Fry formula, go to Fry Testing Exercises, Pfizer Clear Health Communication (http://www.pfizerhealthliteracy.com/improving_fry.html)

SMOG (Simplified Measure Of Gobbledygook) Formula

(Adapted from McLaughlin, G. (1969), SMOG grading: A new readability formula. Journal of Reading, 12 (8) 639-646)

The SMOG formula is a recommended and tested method for grading the readability of written materials. The method is quick, simple to use and particularly useful for shorter materials, e.g., a study's information pamphlet or consent form.

How to use the SMOG formula:

To calculate the SMOG reading level, begin with the entire written work being assessed and follow these steps:

  1. Count off 10 consecutive sentences near the beginning, in the middle, and near the end of the text. If the text has fewer than 30 sentences, use as many as are provided.
  2. Count the number of words containing 3 or more syllables (polysyllabic), including repetitions of the same word.
  3. Look up the approximate grade level on the SMOG conversion table.

SMOG Conversion Table

Total Polysyllabic
Word Count 		Approximate Grade Level
1 - 6 5
7 - 12 6
13 - 20 7
21 - 30 8
31 - 42 9
43 - 56 10
57 - 72 11
73 - 90 12
91 - 110 13
111 - 132 14
133 - 156 15
157 - 182 16
183 - 210 17
211 - 240 18

The SMOG conversion tables were developed by Harold C. McGraw, Office of Educational Research, Baltimore Co. Public Schools, Towson, MD.

Flesch-Kincaid Grade Level Index

The Flesch-Kincaid formula is similar to the SMOG formula. This index computes readability based on the average number of syllables per word and the average number of words per sentence. The score in this case indicates a grade-school level. For example, a score of 8.0 means that an eighth grader would understand the document.

This test is automatically calculated on Microsoft Word documents. After Microsoft Word completes a “Spelling & Grammar’ check, readability statistics are displayed. Generally it must be “turned on” manually to have the program do the readability statistics when a Spelling & Grammar’ check is done on a document.

To “turn on” this function,

  1. Go into your MS Word Program.
  2. Click on the “Tools” bar.
  3. Click on “Options”.
  4. Click on “Spelling, Grammar.
  5. Place a checkmark on “Show Readability Statistics”.

 

SAM (Suitability Assessment of Materials)

Grade-level readability is one of many factors that contribute to the overall readability of written materials. Even materials written on a low grade level may be difficult to comprehend if proper attention is not also paid to organization, layout, and design. To address the overall suitability of materials, including reading grade level, Doak and Doak developed the Suitability Assessment of Materials (SAM).

The SAM guides development and provides a means to assess in six areas: content, literacy demand, graphics, layout and typography, learning stimulation and motivation and cultural appropriateness. The SAM provides a numerical score (in percent) that may fall in one of three categories: superior, adequate or not suitable. A full description of the SAM and a scoring sheet is available in Doak, Doak & Root’s Teaching Patients with Low Literacy Skills, Second Edition, J.B. Lippincott Company, 1996.

A Readability Goal for the Written Materials

The 6 th grade level is a reasonable goal fore most health care materials, about 75 percent of adult Americans will be able to read at this level without difficulty. If you want to make the materials easily readable by 90 percent of adult Americans, it must be written at about the 3 rd-grade level (Doak, Doak, & Root, 1996).

Spanish Readability Formulas

Crawford, A.N. (March 1984). A Spanish language Fry type readability procedure: Elementary level. Los Angeles: Bilingual Education Paper Series, Evaluation Dissemination and Assessment Center, California State University, Los Angeles, 7:1-17.

Gilliam, B., Pena, S.C., and Mountain, L. (1980). "The Fry graph applied to Spanish readability." The Reading Teacher, 33:426-430.

Garcia WF. Assessing readability for Spanish as a second language: The Fry graph and Cloze procedure. Unpublished doctoral dissertation, Teachers College, Columbia University, 1976