Is All Sci-Fi Unbelievable?

Recently, a LinkedIn sci-fi writing group to which I belong posed an important question to its group members. That question was, What comprises believable science fiction writing? I contributed to the discussion (of course!), but I also took a moment to scribble out a longer response to a broader form of the question:

“I think that the problem with the question, ‘What comprises believable writing?’ lies in word choice. ‘Believable’ is perhaps not as accurate as ‘logical.’ We, as readers, should never believe everything we read or hear – not even non-fiction. We should constantly be dissecting and digging into the plot, even of a newspaper article or a historical biography because every author has a bias that is already trapped inside the pages of their works.

The questions in this context really are, Is this author’s train of thought logical according to what I know about the book/genre/style/plot? Are this author’s characters behaving logically according to what I know about them as people, creatures, aliens, etc.? Does the situation logically develop from the premise? ‘According to what I know’ is another important phrase here. Sometimes the plot/character/situation is logical… just not based on the information that the author has provided for us up to this point in the story. Other times, the plot/character/situation is not logical in the real world, but it is perfectly logical within the world that the author is presenting.  

Another very important question also rises in this context: if the plot/character/situation is not developing in a logical manner currently, we must ask ourselves as readers if we are willing to wait until the author provides us with a sufficient motivation within the story for the illogical plot/character/situation.

This question is the critical point where we all differ as readers; we all have a different definition of what “sufficient motivation” really is. We all disagree on the point at which the author ‘proves’ the plot/character/situation is actually logical/worth reading. That is the reason why some readers can be content with never finishing a story and other readers didn't even stop to eat or drink while reading the same story.

However, I think that if we apply these kinds of reader questions (good readers should constantly be asking questions of themselves and of the story) to our personal writing and editing, we can use the answers and the knowledge gained in the creation of all genres. Ultimately, we want readers to become involved in our writing and be able to follow it, not come to an unhelpful jolt in the middle of our stories. We never want to discourage someone from continuing to read our writings from start to finish.”

What are some other factors which make writing believable or logical?