It depends on what the training entitled in terms of extra work or cost. A contract, like a contract or binding agreeent to provide a raise, requires three things: 1) an offer, 2) acceptance of the offer, and 3) consideration. If you offered the employee a raise if she did the training and she accepted that offer, then the issue is consideration. Consideration is something given up or done to bind the contract. If the training was done as part of the employee's work, during work hours, and did not create extra work for her, there is likely no consideration and no contract. On the other hand, if the employee took training on weekends or after work, had to work harder or longer to make up the time spent on training, had to buy her own books or materials, etc., then those things would be very possibly be consideation, creating a binding obligation to give her the raise upon completion.