I think some of these responses are perhaps interpreting "experimental" a bit too narrowly. It seems clear to me that many "modern" writers, if we define modern as meaning the twentieth century, were in fact seeking new, non-traditional uses for the language, and that this could loosely be described as "experimental" in the way we use the word today. Certainly some of the canonical twentieth century authors were attempting to do things with language and narrative that few had attempted before, and some of their efforts came off better than others. I do think, as Post 6 observes, that "modern" is a sweeping term that could be construed to encompass a certain genre of literature (in which case the question is sort of redundant) or a time period.

It seems as though every generation of writers wish to push the limits with their writing in some form or fashion, and the twentieth century writers are certainly no exception to the rule.  I definitely agree that the 'modern' writers attempted to break free from the more traditional forms of poetry, novels, and short stories.  Like a fashion trend, the next generation will always want to define their own sense of style and do things their own way.

Sometimes there is too much distance between a signifier and a signified, and here "experimental" is such a signifier.  The original impetus for this discussion is, I think, legitimate; let me try to reword it:  Is one significant feature of (most) 20th century English literature is that it departs from traditional modes of using the language, and 19th modes of handling narrative?  We can see what the enquirer was getting at.

I too have an issue with "experimental." Essentially, every period's work was novel. Each period throughout history has come to change from the preceding. Writers generally disagreed with what the writers wrote prior to them, and the new writers desired to emphasize new ideologies and characteristics.

Was this experimentation? I do not believe it was.

Modern literature changes as the world changes. Nothing can be stated as experimental in the writer's mind (I would assume). Instead, they were, and are, writing what they wish (like those who came before them).

My objection to the starting point of this discussion is that the terms are so broad as to be meaningless. Including all "modern" (however you choose to define that term) literature in the same statement ignores the vast differences between different genres and different purposes for creating literature.

Certainly there are many types of recently written literature that are experiments in format, language, style, and so forth. However, there are also many contemporary pieces of writing that follow established patterns for very valid purposes.

I still object to the term "experimental".

You're argument against the term "experimental" is a good one, I think. Conventionally, we use the term without reference to the scientific process of creating a stated thesis then testing that thesis, however, in agreement with your larger point, we probably shouldn't deem works "experimental" unless those works were created with the definite intention of breaking from conventions in ways that go beyond commonplace breaks with convention (which happens all the time). 

Just being different from what's come before, in other words, doesn't necessarily make something experimental. It's just new. 

For sake of conversation though, I think we might be served in looking at To the Lighthouse; Mrs. Dalloway; Absalom, Absalom! and Ulysses, works which are significantly different in form and style than works that came before them. 

We might reasonably appy the term "experimental" to these works, if we use the term in its current, popular connotation. At least, I'd make that argument.

I still object to the term "experimental".

Many works that are considered to be examples of modernism in literature are experimental. We might re-situate the question a bit here and ask if works are identified as being works of modernism because they are experimental. 

This is entirely possible. The definition of modernism remains rather loose today but was non-existent during the period now described as the modernism period. The characteristics of modernism have been extrapolated rather than built in through intention.

We continue to actively "create" this movement by looking back, picking and choosing which works from the same time period are examples of modernism. The works usually cited are, yes, experimental, perhaps because this is now how we define the meaning of modernism.

(However, if this is the only definition of modernism, it leaves quite a bit out and also renders the term modernism rather useless. We may as well call the works in question 20th century experimental fiction, right?)

"Orientation" is an ambiguous term, as is Modernism.  But I would challenge the assumption that writers from 1900 on had a motive to "experiment" at all.  They were, it is true, turning their back on the "rules" of previous literary trends, and on "rules" themselves, but they also were not interested in making a new set of rules for anyone else.  Individual expession was the point, inside or outside "rules," was the only criterion, so Joyce, Yeats, Hemingway, Whitman, or whoever you considedr a Modernist, were simply using the English language however it suited their expressive needs.  If the scientific paradigm is inferred by the use of the word "experimental" there was no "hypothesis" to be expanded to a "theory" of literary "rightness."