Although entire books have been written to explain learning, it is actually fairly simple. Learning is any positive change in thinking or behavior.
Generally, ‘positive’ means that it is uplifting or can be used to do something useful, productive, or helpful.
… eXperience …
Experience could be described as an event or process one undergoes, encounters, comes in contact with, meets face-to-face, comes up against, or goes through.
The best experiences give one practical knowledge or wisdom—in other words, one learns or grows as a result.
Design is a method of solving otherwise intractable problems by starting with the solution and working backward to fit to the problem; this “backward” approach is sometimes referred to as solutioneering.
Although design is neither art nor science, it can take advantage of both to generate solutions.
Learning ... eXperience ... Design (or LXD) is—
—any positive change in thinking or behavior which comes as a result of some event encountered or process one has gone through, that has been created through a solutioneering process called design.
So, Learning eXperience Design (LXD) utilizes the characteristics and creative processes around all three separate Concepts.
Some Things that are Not LXD
The three separate sides of this triangle are a good way to describe what learning experience design is not.
Learning Experience (without Design)
In reality, learning and experience are hard to separate. How do you learn without experiencing something? The key, of course, is to try to make the experience a positive one—and that is why design is an essential part of the formula. Without designing the experience, it is as likely to be "meh" as enjoyable (and often is). So, design is an important part of creating great learning experiences.
Learning Design (without Experience)
Although this term is sometimes heard as an abbreviation for Learning eXperience Design, learning design that truly leaves out experience would become mere content design. While content design is an important part of LXD, the ways the learning is experienced is an important part of good learning. Including the word "experience" helps focus on the importance of designing the experience as well as the content.
Experience Design (without Learning)
I would argue that all design is really experience design. After all, what do graphic designers, web designers, interior designers, user experience designers, industrial designers, and even architects all have in common? They are designing an experience. A graphic designer could be called a visual experience designer; an interior designer might be referred to as a spacial experience designer; an industrial designer could be referred to a product experience designer; and so forth. What is different among the different kinds of designers is the medium through which the experience is experienced—the image, the space, the product, etc. In our case, what we want the participant to experience is great learning.
This field has had many names over the years. Among them are instructional technology, instructional science, and instructional design. My degree comes from a university department that has used the label for over a decade, instructional psychology and technology. Stanford University's relevant degree is now called learning, design, and technology (or "ldt"—note the commas!) which has popularized using the word Learning in some degree titles.
Regardless of title, what they all really have in common is that they are trying to teach their students to create good learning experiences.
(I'll cover more on why I like the word design another time...)