Using a questionnaire has proved, in my experience, to be the least effective way to map and understand knowledge gaps, surface issues , to identify worthwhile new practices or opportunities
Knowledge is a complex subject, most people confuse information & knowledge and need exposure & training to understand and appreciate the distinction
A questionnaire will return what the respondent want you to 'see' rather than their assumptions, true experiences, actual issues and deep desires
There are always problems with 'your' interpretation and scoring no matter how carefully the survey wording is crafted and how mant times it is tested
To appreciate knowledge gaps, you need to understand the personal networks and work context - This is impossible to get via a survey - it requires immersion
Answers are clouded by personal and group assumptions / worldviews which are mostly tacit and unarticulated
Awareness of knowledge gaps comes best through conversation and engagement in practice - This awareness is emergent, never complete and strongly dependent on prior experiences and exposures
Surveys tend to overstimate the problem and the returns are very difficult to aggregate for the resons given
May I suggest some alternatives?
Convene an openspace gathering so participants can expore and reflect on their issues and gaps
Conduct an ethnographic, action research project observing and asking questions insitu to obtain situated recall and to document exceptions
Observe rather than ask - people forget, they remember selectively and with constant bias
Knowledge gaps come in many forms, the most prevalent is a lack of a forum (community) to surface distinctions, share insights, support learning and having trusting colleagues to make you aware
Conducting a knowledge mapping exercise is likely to give a more holistic picture and a far better ROI.