The phrase "a special questionnaire" is correct and usable in written English.
You can use it when referring to a specific questionnaire that has unique features or purposes, often in research or survey contexts.
Example: "We have developed a special questionnaire to gather feedback from our participants about the new program."
Alternatives: "a unique survey" or "an exclusive questionnaire".
We developed a special questionnaire including 10 chapters (101 questions).
64 subjects attending three different sessions of 30 min each, filled in a special questionnaire during the experiments.
A special questionnaire (Table 1) was designed to collect data on migraine aura features and HCD during the aura.
A special questionnaire was applied to 72 students, aiming to evaluate their opinion regarding the formative effect of these methods.
This is drawn from the International Passenger Survey - a special questionnaire of some of the people who pass through our key ports.
Dietary habits and eating behaviors were evaluated with a special questionnaire that had been developed for the study, and was found relatively valid and reliable.
This story was so common that interviewers devised a special cook questionnaire, asking what they would cook and the times of the meals.
Since 2000 young adults who live in households that are part of the survey are interviewed regarding their school career and career plans as a part of a special youth questionnaire.
Those with A1C ≥ 7% were interviewed by special questionnaire that was filled out by the medical staff of the clinic.
Those with A1C ≥ 7% were interviewed by special questionnaire, that was filled in by the medical staff of the clinic.
Uniform trained investigators used the special questionnaire containing information of age, sex, tobacco smoking, alcohol intake, family history of cancer, and environmental factors to interview patients face to face after written informed consent.
