As a researcher... you will investigate human limitations and behaviour either academically through a university, or practically through field research; often a blend of both. Your results will shape how ergonomic & usability professionals work.
As an educator... you will teach seminars and conduct field research with students to introduce them to the principles of user-centered design and familiarize them with tools of the trade. Alternatively, you might host workshops for clients who need to involve several/all of their employees in a human factors sector of their company.
As a consultant... you will conduct analyses of work tasks and work environments or products designs, and supplement those analyses with user-testing. The findings from those analyses will directly benefit your clients, whom you will find either because they contracted you, or because you or your organization sought them out.
As an organization member... you will have fulfilled some practical & educational requirements required for entry. You will contribute, both financially and through your efforts, to better the field of ergonomics and/or usability. In return, you will be part of a much larger network that will provide you with experience and opportunities and a greater significance to your work.
As an enthusiast: you might not be qualified or educated in all the skills required to work as an ergonomist or interface designer, but the interests and skills you do have, will serve you well in your own profession and in your life. Many organizations will include you in a smaller capacity and will appreciate your support.
