Look at the price for each package and what it includes. Look at the number of lessons, amount of study material, online technical or other support, and analyze how much you are willing to pay and what you want to learn for that price.
Play a demo version of each course to see which one you prefer: Rosetta Stone, for example, starts you out listening to the language while Visual Link introduces you to vocabulary.
Read reviews and ask people who have these systems for their opinions; these reviews can help you form a realistic idea of what you will get out of the software. Base your opinion on your own learning style and experience with the demos.
Write a list making comparisons between the software. Include items such as "I enjoy the learning style" or "the audio is clear and is easy to understand." Depending on what you need you may want a program with more vocabulary words that will take months to get through or one with a smaller, functional vocabulary that you can use daily.
Purchase the software that best suits your needs using your comparison list.
