Editing Readability (section)

=== Dale–Chall formula ===
{{Main|Dale–Chall readability formula}}
To apply the formula:

# Select several 100-word samples throughout the text.
# Compute the average sentence length in words (divide the number of words by the number of sentences).
# Compute the percentage of words NOT on the Dale–Chall word list of 3,000 easy words.
# Compute this equation from 1948:
#: Raw score = 0.1579*(PDW) + 0.0496*(ASL) if the percentage of PDW is less than 5%, otherwise compute
#: Raw score = 0.1579*(PDW) + 0.0496*(ASL) + 3.6365

Where:
:Raw score = uncorrected reading grade of a student who can answer one-half of the test questions on a passage.
:PDW = Percentage of difficult words not on the Dale–Chall word list.
:ASL = Average sentence length

Finally, to compensate for the "grade-equivalent curve", apply the following chart for the Final Score:
{{Aligned table
|class=wikitable
|row1header=y
|Raw score |           Final score
|4.9 and below |    Grade 4 and below
|5.0–5.9 |           Grades 5–6
|6.0–6.9 |            Grades 7–8
|7.0–7.9 |            Grades 9–10
|8.0–8.9 |            Grades 11–12
|9.0–9.9 |            Grades 13–15 (college)
|10 and above |      Grades  16 and above.}}<ref name="Dale-Chall">Dale, E. and J. S. Chall. 1948. '"A formula for predicting readability". ''Educational research bulletin'' January 21 and February 17, 27:1–20, 37–54.</ref>

The new Dale-Chall formula is:

:Raw score = 64 – 0.95 *(PDW) – 0.69 *(ASL)