This study analyzed data on Nico Nico Douga's view rankings and conducted a quantitative survey of Let's Play content viewers to clarify that the outflow of Let's Play content creators and viewers from Nico Nico Douga was a factor in its stagnation. The data analysis revealed that the number of views of Let's Play videos accounted for a large proportion of the increase or decrease in the total number of views on Nico Nico Douga. The quantitative survey indicated that the decrease in the number of paying subscribers to Nico Nico Douga may reflect the migration of Let's Play video viewers following the departure of Let's Play video creators. In response to these results, this study presented the following considerations: In a situation of conflict between the monetization of Let's Play content and the social norms of the online community, the resolutiont of copyright issues in Let's Play by video game companies has changed the social norms and logic of the online community, stimulating the migration of Let's Play content creators to competing platforms.

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In level design for game development, methods of procedural content generation such as automatic map generation have become standard practice. Several popular algorithms have been proposed for generating naturally shaped stages such as caves and jungles, as opposed to generating stages of artificial regular structures such as schools and cities. However, quantitative evaluation methods for random shapes that do not contain periodicity or regularity have not been established both in academic and industry fields. In fact, the entropy related to the location of rooms and the entropy based on coarse-grained cavity ratios exist, but they are not suitable for the overall structure and impression of the game map. Therefore, we also focus on the microscopic structure of the generated game map and introduce entropy applied with a differential filter as a measure of the overall randomness, showing its effectiveness in capturing the global and microscopic features of the game map. The method proposed in this paper is an effective index for shape evaluation of not only automatically generated maps based on procedural algorithms, but also game maps created manually by creators.

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Statistical hypothesis testing is widely used across research fields; however, its misinterpretation can easily lead to misleading conclusions. This article highlights two common issues: the misconception that non-significant results imply no effect, and the inflation of Type I error rates due to multiple testing. Using the paired t-test as an example, we explain the asymmetry of hypothesis testing, the properties of p-values, and the usefulness of confidence intervals when interpreting non-significant results. Regarding multiple testing, we introduce the Bonferroni correction as a widely used method and briefly compare it with alternative approaches such as the Holm and Benjamini–Hochberg (FDR) procedures. We also discuss the potential of dimensionality reduction techniques, such as principal component analysis, to decrease the number of comparisons. Furthermore, the article emphasizes the importance of research ethics, including transparency in reporting exploratory versus confirmatory analyses and avoiding questionable practices such as p-hacking. Finally, by reflecting on the role of academic presentations as preliminary reports, we suggest practical ways for researchers to enhance the statistical rigor of their studies. By raising awareness of these issues, this article aims to provide researchers—particularly those in applied and interdisciplinary domains—with a clear pedagogical foundation for avoiding common statistical pitfalls and for contributing to more reliable and reproducible scientific publications.

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To increase use of the “Journal Template and Style Manual,” the Editorial Committee organized a session at the 2025 Summer Conference. This contributed article reflects on the content of the session from the perspective of its organizer and presents future initiatives to promote better paper submissions. A survey conducted to gather feedback from the participants yielded generally positive evaluations. Continuing such initiatives and increasing their broader awareness are identified as future challenges.

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DiGRA Japan held its 2025 Summer Research Conference on September 12–13, 2025, at the Tochigi Prefectural Cultural Center in Utsunomiya City, Tochigi Prefecture. This paper provides a record of the conference along with an account of the background leading to its organization.

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This paper is an account of participation in “Replaying Japan 2025,” held at the Royal Melbourne Institute of Technology in Australia.

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From March 17 to 21 in 2025, I attended the Game Developers Conference (GDC) 2025 in San Francisco, USA, and presented at the Educators Summit. This is a record of my participation.

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