SMOG Readability

FormulaThe 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.

Harry McLaughin Ph. D

1.Count 10 consecutive sentences near the beginning, middle, and end of your material (30 total sentences).

Using the SMOG Formula:

2. Count every word with three or more syllables in the 30 sentences, even if the same word appears more than once

3. Add the total number of words counted. Use the SMOG Conversion Table to find the grade level.

4. If your material has fewer than 30 sentences, follow the instructions for “SMOG on Shorter Passages” and use SMOG Conversion Table II.

A sentence is any string or words ending in a period, exclamation point or question mark.

Words with hyphens count as one word. Proper nouns are counted. Read numbers out loud to decide the

number of syllables.

Word Counting Rules:

In long sentences with colons or semicolons followed by a list, count each part of the list with the beginning phrase of the sentence as an individual sentence.

Count abbreviations as if they were not abbreviated. Do not count verbs ending in “ed” or “es” that make

the word have a third syllable.

(for longer materials) Word Count Grade Level 0 - 2 4 3 – 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

SMOG Conversion Table I

Use this formula and SMOG Conversion Table II for material containing less than 30 sentences, but no less than 10 sentences.

Count the total number of sentences in the material.

Count the number of words with 3 or more syllables.

SMOG for Shorter Passages (<30 sentences)

Find the total number of sentences and the corresponding conversion number in SMOG Conversion Table II.

Multiply the total number of words with 3 or more syllables by the conversion number. Use this number as the word count to find the correct grade level from Table I.

(for use with less than 30 sentences) Number of Sentences

Conversion #

29 1.03 28 1.07 27 1.1 26 1.15 25 1.2 24 1.25 23 1.3 22 1.36 21 1.43 20 1.5 19 1.58 18 1.67 17 1.76 16 1.87 15 2.0 14 2.14 13 2.3 12 2.5 11 2.7 10 30.

SMOG Conversion Table II

A sentence is defined as a string of words punctuated with a period, an exclamation mark, or a question mark. Consider long sentences with a semi-colon as two sentences.

Hyphenated words are considered as one word. Numbers which are written should be counted. If

written in numeric form, they should be pronounced to determine if they are polysyllabic.

Proper nouns, if polysyllabic, should be counted. Abbreviations should be read as though

unabbreviated to determine if they are polysyllabic. However, abbreviations should be avoided unless commonly known.

When using the SMOG formula:

If the written piece being graded is shorter than 30 sentences, approach it as follows: Count all of the polysyllabic words in the test. Count the number of sentences. Find the average number of polysyllabic words

per sentence, i.e.:Total # of polysyllabic wordsAverage = Total # of sentences

Multiply that average by the average number of sentences short of 30.

Add that figure on to the total number of polysyllabic words.

Compare the number of polysyllabic words in the SMOG conversion table.

The Raygor Readability Estimatethis readability formula is designed specifically for middle/secondary level reading material. More reliable than formulas like the Fry Readability Graph (1977) that include syllable counts, the Raygor count is also easer to determine.

Alton Raygor (1977)

The RAYGOR GRAPH

Step 1

The Raygor is really a lot simpler than it appears at first. The first step is to count out three 100-word passages, from the beginning, middle, and end of a book. The results of the Raygor are averaged out over these three passages. Don't count any numerals unless written out as numbers – i.e., do not count “43” but do count “forty-three”.

STEPS in conducting The Raygor Readability

Step 2

Next, count how many sentences you have. If the 100-word limit breaks a sentence in two, count all the words in that sentence, then estimate how many tenths of the sentence are used in your 100-word count. For instance, if you had 15 words in the entire sentence and only seven were part of your 100-wordcount, you would estimate .5 (15/7 = 2 1/7 = .5).

Step 3

Now take the 100-word passage and underline the words with 6 or more letters. Count how many words are in the passage.

Step 4To plot the results on the Raygor, find the total number of sentences in your passage on the vertical axis (left column) of the Raygor scale and place a dot on the margin closest to your number. Next find the number of words having six (6) or more letters on the horizontal axis (bottom scale) and again place a dot closest to that number. Now find the place where the dots intersect on the graph to arrive at your grade level. Remember that the grade level is only valid within the “parallel” lines. If your plot is in the top left area of the grid or the bottom right (outside of the parallel lines) your total is invalid for the purposes of the estimate.