The Vienna Formula for Technical Texts is used to calculate the readability of German-language texts. It indicates which school grade level a non-fiction text is suitable for. The scale starts at grade 4 and ends at 15, with levels above 12 being considered more as difficulty levels rather than school grades.
How the Wiener Sachtextformel Works
The Wiener Sachtextformel (Vienna Formula for Technical Texts) was developed by Richard Bamberger and Erich Vanecek to calculate the readability of German-language texts. It provides an indication of which school grade level a non-fiction text is suitable for.
The formula uses the following variables:
MS = Percentage of words with three or more syllables
SL = Average sentence length (number of words)
IW = Percentage of words with more than six letters
ES = Percentage of one-syllable words
There are four variants of the Wiener Sachtextformel:
WSTF1 = 0.1935 × MS + 0.1672 × SL + 0.1297 × IW - 0.0327 × ES - 0.875WSTF2 = 0.2007 × MS + 0.1682 × SL + 0.1373 × IW - 2.779WSTF3 = 0.2963 × MS + 0.1905 × SL - 1.1144WSTF4 = 0.2744 × MS + 0.2656 × SL - 1.693
The scale starts at grade 4 and ends at 15, with levels above 12 being considered more as difficulty levels rather than school grades. A value of 4 represents a very easy text, while 15 indicates a very difficult text.
Interpretation of scores:
4-5: Very easy text, suitable for 4th-5th grade
6-7: Easy text, suitable for 6th-7th grade
8-10: Average text, suitable for 8th-10th grade
11-12: Difficult text, suitable for 11th-12th grade
13-15: Very difficult text, suitable for college level and above
The Wiener Sachtextformel is particularly useful for assessing German non-fiction texts, technical documents, and educational materials. It helps ensure that texts are appropriate for their intended audience, supporting better comprehension and learning outcomes.