In hiring a new team member, there is a debate about the degree of importance of having theoretical background compared to practical experience. Theoretical background is gained through academic education, formal training, self-studies and preparations related to certifications. While practice experience comes from actual exercise of skills and competencies in battle field (work environment of course). In addition, practice experience could come from extensive discussions with domain experts.
Practical experience without theoretical background is similar to working with a device without reading its manual. It is probable that you will miss some functions or misuse others. Reading user manuals will help a lot for better understanding of this device.
On the other hand, reading the manual without exercising its instructions on the device, will not make you an expert with using this device. It will take long time to recall instructions for something requires seconds from somebody knows it.
When you interview someone for hiring, you need to make sure he has the right ingredients with proper amounts of theory and practice. Academic education can be easily proven through certificates. However, practical experience is hard to prove (other than getting some guidance from a well-written CV).
One of best techniques is scenario questions. You tell a short story to set the context of the interview and ask a question about the response or a solution for a specific situation within this context. The language of the candidate reply and its logical order should demonstrate his theoretical background. The selected decision should show his practical experience factor.
In conclusion, both are important and you should consider both in your evaluation.
- The 6 Huge Hiring Mistakes Everyone Makes (fastcompany.com)
- Practical and Theoretical Knowledge (orgtheory.wordpress.com)