Readability test

A readability Index equation, or a method which attempts to determine the readability of a text. It fulfills the function of a mathematical metric.

Method

The first readability formulas have been developed for the English language, they are there but also for other languages ​​such as German, French, Spanish, Dutch, Danish and Swedish. In general it can be said that all readability formulas are language - and text- genre -specific, So for example, the Flesch Reading Ease index can not be applied in unchanged form on German -language texts, unless you want to prove that German for foreigners is difficult. However, it is possible to calibrate these and other indices for languages ​​other new and then use appropriate.

For the English language, there are more than 200 procedures. This list covers only the most popular from:

Flesch Reading Ease

The readability index Flesch Reading Ease, Flesch - called degrees, is a numerical value for the readability, which can be calculated from a text. The higher the value, the more readily understood, the text. Good to understand texts have a value of about 60 to 70. The Flesch Reading Ease is matched in their calculation on the English language. It is calculated using the following formula:

With:

• ASL. The average sentence length (average sentence length ) are calculated by dividing the number of words divided by the number of sentences of the text in the text.
• ASW. The average number of syllables per word ( Average Number of Syllables per Word) are calculated by dividing the number of syllables of the entire text is divided by the number of words in the text.

The procedure was developed by Rudolf Flesch.

Toni Amstad could transfer the formula to the German language. Above all, the word factor had to be recalculated, as the German words are on average longer than English, while the rates are about the same length. The definition of his formula:

The following table shows a rough classification or classification based on the age or education.

Flesch - Kincaid Grade Level

This readability index tries as the Gunnig -Fog index ( see below), the readability expressed in the number of school years, which must have completed a reader to understand the text. He, too, is matched to the English language and the American school system. The Flesch - Kincaid Grade Level is calculated as follows:

ASL and ASW as explained below Flesch Reading Ease.

As one easily checks easily, has the record length when FKGL a greater impact on the index than in the FRE. For both indices, however, dominated by the word length, which explains the limited applicability to the German language, with its many compound words.

Example:

The not-too- difficult -to-understand sentence. " All my ducks swimming on the lake, head under the water, tail in the Hoh " has 14 words and 22 syllables, so ASL = 14, ASW = 1.57, FRI = 60, FKGL = 8.4 ( ).

Gunning -Fog Index

Developed by Robert Gunning Fog Index is also about the number of years of schooling, which must have completed a reader to understand the text. The Gunning Fox index is also tuned in its calculation on the English language and in his interpretation of the American school system. It is calculated using the following formula:

Have the total number of words in the text, at least three syllables: W: the number of words in the text, S: the number of sentences in the text, D

The method and the exact criteria are in words:

The result is the Gunning -fog Index.

Vienna factual text formula

The Vienna factual text formula used to calculate the readability of German texts. It indicates for which grade a factual text is suitable. The scale starts at grade 4 and ends at 15, which should be spoken rather than of difficulty levels from grade levels from level 12. A value of 4 is therefore very simple text, whereas 15 denotes a very difficult text.

The formula was established by Richard Bamberger and Erich Vanecek.

MS is the percentage of the words having three or more syllables,

SL is the average sentence length (number of words),

IW is the percentage of the words with more than six points,

ES is the percentage of monosyllabic words.

The first Viennese factual text formula

The second Viennese factual text formula

The third Viennese factual text formula

The fourth Wiener factual text formula ** ( in terms of the school year ) **

The example with the duck returns to the first WSTF an index of

For a theoretical justification

Readability formulas are widely established in research. Many who deal with readability formulas, but ask yourself the question why one can obtain information about the readability of text, taking into account only very few criteria. One has but slightly under the impression that word and sentence length should be no more valid criteria. But you look at which other criteria, these two mentioned - and others - are linked, you can see that although only two text properties are measured directly, indirectly but quite a few others are also considered.

Automatic determination of readability indices

Most early readability formulas were originally designed for manual analysis. Hence also given in some publications proposal to take samples of 100 words. The automatic determination of text readability is a field of language technology. Depending on the formula different claims are thereby placed on a computer program. While the recognition of sentence boundaries usually works as a prerequisite for the counting of sets reliably, the correct separation of the input text into words ( tokenization ) is already often unclear. Also the counting of syllables can be accomplished with the computer only approximate. Since people make mistakes, the original formulas are automatically adjusted so that they tolerate these errors more or less. However, make computer errors other than humans, hence the constants in the formulas should ideally be adjusted. Less susceptible to this problem are newer formulas that have been designed from the outset for the automatic evaluation.