A respondent who used one service on three days and another on three different days is counted at 3 days rather than 6, so August's figures may understate frequency relative to an overall-use question.
【局限】研究承认其方法可能低估实际使用频率，因为多服务用户的使用天数被取最大值而非累加。这种限制影响了数据的准确性，特别是对同时使用多个AI服务的用户群体。
van Smeden, M., Lash, T. L., & Groenwold, R. H. H. (2020). Reflection on modern methods: Five myths about measurement error in epidemiological research. International Journal of Epidemiology, 49(1), 338–347. https://doi.org/10.1093/ije/dyz251
Laghaie, A., & Otter, T. (2020). Measuring evidence for mediation in the presence of measurement error [Preprint]. PsyArXiv. https://doi.org/10.31234/osf.io/5bz3f
Maarten van Smeden on Twitter: “This is a kind reminder that most issues with data (e.g. measurement error, incomplete data, confounding, selection) do not disappear just because you have N = ginormous” / Twitter. (n.d.). Twitter. Retrieved July 19, 2020, from https://twitter.com/MaartenvSmeden/status/1283313496382373890