“…Data-driven models can also be combined with graphical models ( Zhou et al, 2020 ; Song et al, 2019 ; Moon et al, 2019 ; Shi et al, 2020 ; Wu B. et al, 2020 ; Xu et al, 2020 ), rule-based or slot-filling systems ( Tammewar et al, 2018 ; Zhang Z. et al, 2019 ), a knowledge-base ( Ganhotra and Polymenakos, 2018 ; Ghazvininejad et al, 2018 ; Luo et al, 2019 ; Yavuz et al, 2019 ; Moon et al, 2019 ; Wu et al, 2019 ; Lian et al, 2019 ; Zhang B. et al, 2020 ; Majumder et al, 2020 ; Tuan et al, 2021 ) or with automatic extraction of attributes from dialogue ( Tigunova et al, 2019 , 2020 ; Wu C.-S. et al, 2020 , 2021 ; Ma et al, 2021 ) to improve the personalised entity selection in responses. Methods that adopt transfer learning ( Genevay and Laroche, 2016 ; Lopez-Paz and Ranzato, 2017 ; Mo et al, 2017 , 2018 ; Yang et al, 2017 , 2018 ; Wolf et al, 2019 ; Golovanov et al, 2020 ), meta-learning ( Finn et al, 2017 ; Santoro et al, 2016 ; Vinyals et al, 2016 ; Munkhdalai and Yu, 2017 ; Madotto et al, 2019 ; Zhang W.-N. et al, 2019 ; Song et al, 2020 ; Tian et al, 2021 ) and key-value memory structures ( Xu et al, 2017 ; Kaiser et al, 2017 ; Zhu and Yang, 2018 , 2020 ; de Masson d’Autume et al, 2019 ) could provide effective insights to alleviate data scarcity and enable quick adaption to various users through improving few-shot and lifelong learning capabilities of the dialogue models ( Wang et al, 2020b ).…”