I'm currently doing research on student's motivation in learning English. And I'm looking for the best way to measure motivation. Is it through questionnaire, interview or etc? Do we need to measure in certain period of time?
The answer(s) will depend on why you are doing this research and on the hypothesis(es) you want to analyze. For example, are you trying to prove the most critical factors that drive extrinsic motivation, or intrinsic motivation...or something else? And are you conducting a quantitative or qualitative study? The type, scope of, and rationale for your study will help you identify the kinds of instruments you may want to use. Then you may want to review the extant instruments that have already been deemed valid and reliable, and that fit with your answers above. For example, questionnaires are beneficial if you want a large number of responses, but the caveat with using this instrument is the limited number and depth of questions you can ask before response boredom sets in. Interviews and focus groups are beneficial if you want to dig deep into how and why students get motivated, but the time-consuming nature of this data collection method generally means a smaller number of respondents (unless time is not an issue for you).
I recommend you review texts on how to conduct research, such as Practical Research: Planning and Design by Paul Leedy and Jeanne Ellis Ormrod. This reference is concise and clear and has helped me a great deal in my own research.
@Steven Thank you for the illuminating answer. My research design is quantitative. I am trying to discover types of motivation among students having bilingual exposure in Pesantren and the correlation between their specific type of motivation with their English proficiency (measured through standardized national exam). I have reviewed some literatures related to the topic, one of them is belong to Zoltan Dorney.
The thing coming up in my mind is 'should we assess motivation periodically" in order to know its fluctuations and how strong it may correlates with their language proficiency.
U will need to frame a five or seven point likert scale with questions covering all essential dimensions of motivation for English language.
U will have to clarify whether u want to distinguish between different types of motivation like Motivation for poetry or motivation for communication motivation for literature etc or u just want to know the degree of motivation?
If what you mean is to improve teaching efficiency, anonymous questionaires will be helpful. Now, if what you mean is to consider motivation as a grading parameter, that might turn out to be unethical; not necessarily, of course, but it's something to be analyzed thouroughly.