I rarely see them mentioned in the same category.  But games like Zork and The Hitchhiker's Guide to the Galaxy are arguably Adventure Games with no graphics.  Do you consider the absence of graphical representation to be key?

Yes. And considering the term "graphic adventure game" was coined to distinguish graphics based adventure games apart from text based adventure games, I feel it's not really much of a debate whether they are or aren't.

Of course, I assume this is more about everyone's opinion and feelings about the matter, not what is the "most factually correct", but my personal opinion is based on that fact.

I think they are too. How can they not be? Graphical AGs are a direct evolution of text adventures.

Yes.

First text Adventure (Colossal Cave) = Mercury mission: first man in space.
First graphic adventure (Mystery House) = Apollo 11: Moon landing.

Yes they are, you just use your imagination to paint the scenes. You can call it technological limitation or design choice or both. Its common in arts that evolution comes from limitations. For example in Cinematography at first movies contained no editing, but soviet directors faced a problem, they didn't have enough film reels, they were expensive. So pioneers experimented in shooting with fewer shots, tying the scenes together... and then editing was born and has become an integral part of a movie. It was practical and you could use the technic for all sorts of ways, for symbolism, to express feelings, to tell a story. Bigger more complex films became possible. Then Alfred Hitchcock took a step back, he directed the film "rope" which contained minimal invisible editing cuts, essentially designing a movie with a continuous flow... no edit! A masterpiece of expertise and an intense experience. There are no limitations and definitions in cinematography and art in general. You can tell a story writing a book but also through a movie, people still write books not just because there are financial constraints, but because it is a unique medium. Even in the future if with AI financial constraints become trivial, literature will stand. From cave paintings to Renaissance and to Cubism, "evolving" and "devolving" it's the same with Adventure games. No graphics and a Text input is not only a limitation but an expression of the medium we call "adventure games". Look at games like Analogue: A Hate Story and No Case Should Remain Unsolved and how they built in mechanics and storytelling without the reliance to graphics. Of course they contribute to the medium and i consider them adventures. Another great example is how spooky low pixel horror games are like the "Last door" ones. I once played a Low pixel experimental AGS game (Don't remember the name), in the game I entered a bar, then the bathroom and saw a dead body and an axe beside it, I took the axe, then I exited the bathroom axe in hand, a patron at the bar said "Hey that's a nice rose!", why did I think it was an axe...my mind assumed it. In all the games i mentioned in the absence or limitation of graphics the mind fills the gaps creating intense personal experiences unique for each player. Its the same with the input, doesn't matter if it's text parcel, or a joypad, or point and click or touch or VR or whatever. An adventure game remains an adventure, their main characteristics of storytelling, puzzle solving and exploration don't change with the absence of graphics (for me at least)

Simply YES, I definitely do. When there is interaction and decisions and consequences, it's an adventure for me.

Oh yes, they definitely are adventure games. I personally don't enjoy them at all, but they are the clear predecessor of the graphic adventure.

  Do you consider Text Adventures to be Adventure Games?

Yes, I have always thought they were part of the same genre. I initially got started with Everybody Loves a Parade, which is average quality in hindsight, but a cherished starting point nevertheless. Later on I discovered excellent games like The PK Girl, which I still would recommend wholeheartedly.

I rarely see them mentioned in the same category.

Here's where things start to get really interesting. Text-only adventures were the de facto standard until technology evolved and eventually split the medium into three different factions. The interactive fiction community. Visual novel fans. Graphic adventure enthusiasts. That's the main reason why you rarely hear them mentioned or grouped together, because hobbyists had already found their preferred niche circle.

The interactive fiction community is the most traditional of the three, favouring a text-only experience and a large variety of interactions. I love the attention to detail that naturally gets put into the exchange between the player and the objects in-game. There is a sense of agency and freedom in text-only adventures that trumps even most RPGs and other genres. ADRIFT engine games are the type I'm most familiar with.

Visual novels are the middle ground between text adventures and graphic adventures. There is a specific term within the visual novel community known as a kinetic novel, which is a linear non-interactive story book. Branching visual novels with multiple endings are also common, they are more akin to choose-your-own adventure style, the grandest example being Ever 17 in my personal opinion.

Graphic adventures are the bulk of what you see these days, but the baseline design principles instilled by pioneering text adventures still lingers meaningfully, which usually gets represented as dialogue trees for the core structure.

But games like Zork and The Hitchhiker's Guide to the Galaxy are arguably Adventure Games with no graphics.  Do you consider the absence of graphical representation to be key?

It depends on the circumstances. With The Hitchhiker's Guide to the Galaxy game being based on a book, in that instance you would certainly want your imagination to fill in the gaps. The BBC website has released a 30th anniversary edition where you can play the game for free inside your web browser. But unfortunately it comes with new graphics showing what the locations look like.

On the other hand, The PK Girl has graphics mixed into a text-only interactive engine, but I still enjoyed it.

Absolutely. I'm not really interested in playing them, but I do recognize them as games with a strong narrative focus and puzzles. I kind of think the question itself is kind of weird -- Do you consider games with a parser interface as an adventure game? Do you consider games with CGA graphics as an adventure game? The interface and presentation doesn't really matter in this context, does it?

What about you, Melendwyr? Why do you ask?