Under common-law rules, anyone who performs services for you is your employee if you can control what will be done and how it will be done. This is so even when you give the employee freedom of action. What matters is that you have the right to control the details of how the services are performed.
Example: Donna Lee is a salesperson employed on a full-time basis by Bob Blue, an auto dealer. She works 6 days a week, and is on duty in Bob's showroom on certain assigned days and times. She appraises trade-ins, but her appraisals are subject to the sales manager's approval. Lists of prospective customers belong to the dealer. She has to develop leads and report results to the sales manager. Because of her experience, she requires only minimal assistance in closing and financing sales and in other phases of her work. She is paid a commission and is eligible for prizes and bonuses offered by Bob. Bob also pays the cost of health insurance and group-term life insurance for Donna. Donna is an employee of Bob Blue.