Purpose: To investigate whether short German sentences that have been developed to be highly comparable in number and length of words, as well as in difficulty and construction, are reliable and valid test items for measuring reading speed in order to use them for measuring simultaneously reading acuity and speed with the "Radner Reading Charts".
Methods: Tests were performed in 198 persons: 99 university students (average age 23.6+/-2.8 years) and blue-collar apprentices (average age 18.4+/-2.5 years). Reading speed and the number of errors were determined first with 24 sentences for our recently developed German reading charts (14 words equal in difficulty, length and construction) and secondly with long paragraphs of the "Zuercher Reading Test" (ZRT; paragraphs 3-5, 261 words).
Results: The overall mean reading speed obtained with short sentences was 209.6+/-41.0 words per minute (wpm), compared with 169.2+/-35.0 wpm for the ZRT ( P<0.001). The correlation between the short sentences and the ZRT was high ( r=0.9). Students read faster and made fewer errors than did the apprentices. Reliability analyses yielded an overall Cronbach's alpha coefficient of 0.98. The coefficient of selectivity of the 24 sentences (test items) varied from 0.75 to 0.88.
Conclusion: The present study indicates that the 24 short single sentences we have tested are highly comparable in terms of both lexical difficulty and reading length, and it has demonstrated the validity and reliability of such sentences as test items for determining reading speed.