## 4 Dataset  
The raw transcription data collected by the conversation collection protocol is shown in Table 1. We collected conversations from 67 children aged 5 to 6 years. A total of 1800 utterances were chosen from among them. Of the 1800 selected utterances, 250 are utterances that should be answered by changing the topic, and the remaining 1550 are utterances that should be answered by maintaining the topic.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Speaker** & **Utterance (Kor)** & **Utterance (Eng)** & **Category** \\ \hline Expert & daehwaga mueos-inji al-ayo? & Do you know what a conversation is? & Procedure Explanation \\ \hline Child & aniyo. mollayo. & No. I don’t know. & Procedure Explanation \\ \hline Expert & daehwaneun yeoleosalam-i gat-i & & \\  & isse-eul tate seolo mal-eul & & \\  & jugobadneun geos-eul & The conversation is about talking & \\  & daehwalago haeyo. jigeum ulido & to each other. When we talk like & \\  & daehwalaeul hago & this, it calls the conversation. & \\  & issneun geoyeyo. & & \\ \hline Child & ne & Yes. & Procedure Explanation \\ \hline Expert & yeogie issneun geulim kadeu ne & & We’re going to look at the four & \\  & gaeleul bogo daehwaleu lal & picture cards here and talk to & \\  & geoyeyo. geulim-e daehae & & \\  & seolmyeonghaneun ge anila & & \\  & gieogenaneu geoleul & & \\  & yaegihamyeon dbrae. hana & & \\  & gollabolkkaya? & & \\ \hline Child & ne. gollas-eoyo. (family picture) & Yes. I picked (family picture) & \\  & & & (topic selection) \\ \hline Expert & geuleom yaegileul haejuseyo. & Then please talk about family & Conversation initiation \\ \hline Child & gajog-ilang yeohaeng-eul & I went on a trip with my family. & \\  & gass-eoyo. & & (topic maintenance) \\ \hline Expert & yeohaeng-eul gass-eoyo? & Did you go on a trip? & \\  & child & gajog-ilang imjingag gaseo & I went to Imjingak with my family & \\  & lolleokoseutteo tass-eoyo. & and rode the roller coaster. & (topic maintenance) \\ \hline Expert & lolleokoseutteo tass-eoyo? & Did you ride the roller coaster? & \\  & child & ne ollagassda naeyleogassda & Yes, I rode it up and down & \\  & haneun geosdo tassgo & & (topic maintenance) \\ \hline Expert & ollagassda naeyleogassda haneun & You also rode up and down rides. & \\  & geosdo tassgo geuligo? & And then? & (topic maintenance) \\ \hline \multicolumn{4}{c}{mediated syncope} \\ \hline Child & deo eobs-eoyo. & No more. & \\ \hline Expert & ibeon-eneun jangangam & \\  & yaegileul haebolkka? joh-ahaneun & \\  & jangangam iss-eoyo? & & \\ \hline \end{tabular}
\end{table}
Table 1: Transcribed examples of data collected by the conversation collection protocol. The same utterance is expressed in Korean and English.  
Table 2 shows a data sample with structured data for training the model. The label column indicates whether the topic should be maintained or changed in response to the child's utterance. The label is that the expert directly listened to the recorded conversation, and the responses to what the child said were classified as maintaining the topic or changing the topic. The topic change utterances are typically obvious, such as \"dee oobs-eoyo.\" (\"No more.\"), and \"geuman hallaeyo.\" (\"I want to quit.\"), as seen in Table 2.  
In order to maintain the topic, it is necessary to respond with a questioning-like response so that the topic is maintained through the child's utterance. We discovered that segmenting some sentences of a child's utterance could produce a questioning-like response. Because Korean has a fairly free sentence structure, meaning can be conveyed even if the subject is removed or the word order is modified. Therefore, it is possible to create a natural questioning-like response even by segmenting a sentence based on the segmentation point in an utterance. We constructed the data by marking the segmentation point (<S>) in children's utterances, and it is shown in Table 2.