As always when dealing with any kind of model that helps us communicate and understand the abstract world of our minds, our existence and relationships with each other, nicely summarised by George EP Box: "all models are wrong, some are useful".
This is a free assessment, and there are several others that you can freely download. I liked this one as it is a "1 stop shop" document that you print out, fill out, score quickly on the reporting sheet, and finally receive additional insights at the end. And anyone can complete this simply and quickly.
Printer and 8 pages
Give the link or 8 page print-out to the coachee: Kolb Questionnaire. Again I think the best time to do the assessment is in the morning, before work really starts.
When the assessment is complete, the coachee and you will have the coachee's 4 Kolb styles - Activist, Reflector, Theorist and Pragmatist allocated to very strong preference, strong preference, moderate preference, low preference or very low preference.
You now have material you can use to support the coaching goals and plans where learning is required. You also have the approach you need when explaining concepts to the coachee - a real time saver and much more enjoyable experience for you and the coachee as compared to approaching from the worst angle.
Personally, once I realised what my preferred/natural Kolb learning approach was, I realised how I could learn better and more quickly in the same amount of time.
The future no longer belongs to those who learn the fastest. The future now belongs to those who learn the right things the fastest. Kolb learning styles assessment is just another practical tool to help me and my coachees discover their best learning method, and give us some "Slack" to identify what are the right things. Really useful stuff!