<hi xmlns="http://www.tei-c.org/ns/1.0" style="font-size:12pt">According to Griffiths & Steyvers (2004), the topic model has the best quality when the sum of Alphas of all topics is equal to 50. This is probably the reason that in MALLET 2.0.7, the default value of the sum of Alphas was set to 50, while in MALLET 2.0.8, the value is reduced to 5. According to the supervisor of MALLET, David Mimno: “The general experience was that 50 was too large, and that 5 is a better default.”</hi><ref xmlns="http://www.tei-c.org/ns/1.0" target="ftn1" n="1" /> <hi xmlns="http://www.tei-c.org/ns/1.0" style="font-size:12pt">Since there are different opinions on this issue, it is interesting to test how Alpha affects LDA topic modeling, especially on different types of text collections that are not in English. Therefore, this paper presents a study on evaluating Alpha on two German text collections and aims to understand the influence of hyperparameter Alpha from two perspectives: topic modeling based single-label document classification and topic coherence, representing the quality of the topic model and the quality of the topics, respectively.</hi>