How to Measure Readability of Printed Education Materials

What Is Readability In Fact for Printed Educational Material

    Readability is not a new concept but rather has been a concern of primary and secondary school educators and educational psychologists for years. In the 1940s, there was a great upswing in attempts by educators and reading specialists to develop systematic procedures by which to objectively evaluate reading materials. Readability is defined as “characteristics of reading materials that make material ‘easy’ or ‘difficult to read” (Kahn & Pannbacker, 2000, p.3). Today, more than 40 formulas are available to measure the readability levels of PEMS.

Purpose of Readability of Educational Material In Nursing Education

    Readability indices have been devised to determine the grade level
demand of specific written information. Although they can predict a level of
reading difficulty of material based on an analysis of sentence structure and
word length, they do not account for the inherent individual variables that
affect the reader, such as interest in or familiarity with the subject itself
or the actual content of the materials (Doak et al., 1996).

Measuring Readability By Formulas In Nursing Education

    Even though materials may have similar readability levels as
measured by some formula, not all readers will have equal competence in reading
them. For example, a patient with a long standing chronic illness may already
be familiar with vocabulary related to the disease and, therefore, may be able
to read specific grade level materials much more easily than a newly diagnosed
patient, even though both individuals may have equal literacy skill with other
types of material (Doak et al., 1985).

    As assessment tools, readability formulas
are useful but must be employed with caution because the match between reader
and material does not necessarily guarantee comprehension (Aldridge, 2004;
Davis et al., 1998). Readability formulas were originally designed as
predictive averages to rank the difficulty of books used in specific grades of
school not to determine exactly which factors contribute to the difficulty of a
text. Educators should exercise caution when assuming that people can or cannot
read instructional material simply because a formula based readability score
does or does not match their educational level.

    Even though these simple instruments are practical tools for
assessment of literacy, their utility is limited because they cannot determine
the cause or type of reading and learning problems (Davis et al., 1998).
Therefore, although readability formulas are easily applied and have proven
useful in determining the reading grade level of a text, when used alone they
are not an adequate index of readability (Badarudeen & Sabharwal, 2010;
Davis et al., 1998; Doak et al ., 1996; Doak & Doak, 2010).

    Readability formulas are merely one useful step in determining
reading ease relative to a specific document. Many suggest researchers using a
multimethod approach to ensure readability that is, they suggest applying more
than one readability formula to any given piece of written material as well as
taking into account the reader and other material variables (Doak et al., 1996;
Ley & Florio, 1996). Formula scores are simply rough approximations of text
difficulty. Human judgment is always needed in conjunction with formula based
estimates to determine the quality of PEMs.

What are Readability Formulas and How They are Formed

    Readability formulas are mathematical equations derived from
multiple regression analyzes that measure the readability levels of PEMS by
determining the correlation between an author’s style of writing and a reader’s
ability to identify words as printed symbols within a context (Doak et al.,
1996). Most of them provide quite accurate grade level estimates, give or take
one grade level, with 68% confidence on average. In many respects, a
readability formula is like a reading test, except that it does not test people
but rather written material (Fry, 1977).

    The first guideline to remember is that read ability formulas
should not be the only tool used for assessing PEMs. The second rule is to
select readability formulas that have been validated in the reader population
for whom the PEM is intended. Several formulas are geared to specific types of
materials or population groups (Wang, Miller, Schmitt, & Wen, 2013).

    Ley and Florio (1996) and Meade and Smith (1991) conducted
extensive studies of the most commonly used formulas and reported on their
reliability and validity when used to measure health-related information.
Particularly, the Flesch, Fog, and Fry formulas showed strong correlations with
health-based literature (Horner et al., 2000). Further, the Flesch, Fog, and
Simplified Measure of Gobbledygook (SMOG) formulas have proven successful in
evaluating Internet-based educational materials (Antonarakis & Kiliaridis,
2009; Laplante Lévesque, Brännström, Andersson, & Lunner, 2012). 

    Because so
many read ability formulas are available for assessment of reading levels of
PEMs, only those that are relatively simple to work with, are accepted as
reliable and valid, and are in widespread use have been chosen for review here.