When we read we engage and respond in many different ways and at different times - through browsing before hand, through scanning, through reading, through reflecting, through recollecting.
As we read, we engage with thought, action and feeling towards the beings (human, animal, imagined etc) we recognise and who we come to care about - caring may be because we feel warm towards them or quite the opposite - or, as is most likely, with changing feelings.
The protagonists in a story 'take us' through the action and thought. Some people call this identification, meaning that we hope that we are like the protagonists, but it could also be described as a matter of a reader accompanying the protagonist, choosing to go with them on their mental or physical journey(s) in the book.
This part of the process can involve different kinds of wishes, hopes, dreads, envies and the like: emotional one to one feelings as if they are people we know.
In order to do this we have to be able to do several other things: 'recognise' the text - that is see that it is like another text. This is 'intertextual'. We have already seen or heard something like it, and so we can see and hear things in this that we can recognise and understand or compare with another text.
We will also need to make comparisons with our own life experiences, emotional, rational and the rest.
We will engage in a process of persistent questioning of what's going on in a text: around such things as 'would this happen?' 'would I think this?' 'Why is this person doing that?' 'is this person doing that because...?'
These questions are based on 'harvesting' (as well as the intertextual and experiential approaches). This is 'intratextual' - going on inside the text, harvesting up what has happened before so that we can make sense of what we're reading at that very moment and then wondering about what might happen next - ie predictions.
It's usual to talk about 'character' and our responses to character. I think that's misleading as the characters are always interacting with something - other characters, or physical events: landscape, weather. So, what we're reacting to really are interactions and outcomes. It's always dynamic between people or between people and things. We wonder about the significance of these, sometimes at a moral level, sometimes emotional, sometimes rational, thought-out conclusions e.g. 'that was fair', 'that was unfair'.
Much of the above involves us in making 'analogies' between what is going on in the book, and what we know from real life and/or from other texts. From the very youngest children to adults we are able to do this highly sophisticated, and ultimately 'abstract' thing: we select from what we read and we select from our experience (or our experience of another text) and we compare our selections with each other. 'That's like when...' The moment we make selections and comparisons we are engaged in a form of abstract thought: we are creating 'sets' or 'series' or 'schemas'. Much of what goes for 'comprehension' in schools prevents us from making our own schemas. We have to do 'retrieval', 'inference' and 'chronology' and there isn't time or space to let us (the students) make these schemas. And yet they are at the heart of 'response'.
We carry our reading experiences with us forward from what we have read. They are mental libraries - but more dynamic than that, more fluid. Scenes, feelings, characters, outcomes, interactions stay with us into life, into further reading , into our interactions with other people or with other art forms. We make comparisons, and we make evaluations, and assessments of what these things 'mean' or why they are 'significant' or 'important to us'.
At any point we can surround any of this, or 'inform' it with 'extra-textual' material about authors, social circumstances of the writing, history, and inform ourselves in relation to the question 'why was this written?' 'What were the intentions?' 'how did it relate to the audience(s) of the time of its writing?' 'What significance did it have then?' These kinds of questions will inevitably affect how we respond to what we read, either at the time or later. It's as if we make the text more 3-dimensional, we get round behind it. We don't have to do this, but it's possible and enjoyable.
We can also compare 'reception' - consider how the book I'm reading now, was read last year, ten years ago, five hundred years ago by others. And this might tell me something about the story, the telling, or the times in which the book has played a part in people's lives.