I am doing a research on Vocabulary journal and how improving vocabulary might help in increasing confidence level among learners specifically in writing. I would really appreciate any questionnaire related to this topic. Thanks in advance.
Tunes of relevant material available on many website scholer.google.com you could find most of the stuff. Subject to your research question and specification! If you're degree of attachment with any teaching or research institute or nature of intuition, hopefully, you might would have access facility to many material too.
I don't know if these might be your case, but here are some articles where questionnaire are used: Frankenberg-Garcia (2015): DOI: 10.3366/cor.2015.0081; Giampieri (2020): Article Data-driven learning in English for academic purposes class
You could check out the writing self-efficacy scales validated by Teng et al. (2018) and Sun et al. (2021). Below are the full citations.
Sun, T., Wang, C., & Kim, S. Y. (2021). Psychometric properties of an English writing self-efficacy scale: Aspects of construct validity. Reading and Writing. https://doi.org/10.1007/s11145-021-10206-w
Teng, L. S., Sun, P. P., & Xu, L. (2018). Conceptualizing writing self-efficacy in English as a foreign language context: Scale validation through structural equation modeling. TESOL Quarterly, 52(4), 911–942. https://doi.org/10.1002/tesq.432