for my research I have a hypothesis containing a categorical IV (positive or negative article that the participants have to read) and a continuous moderator (ideology level of the participant). The x axis is the evaluation that participants are giving (by answering different questions on a 7-point-scala). On this following graph, you can see the interaction I'm suspecting (I further elaborate the concept in the last paragraph).
My question is, how can I write this down as a hypothesis if the moderator is continuous? It's clear to me how to do it when it's categorical and somehow I just seem to find examples of categorical moderators. I'm aware that the question might be really simple, but I'm really having trouble visualizing all this, as I imagine that I can't speak of 'low', 'moderate' and 'high' levels in my hypothesis? (again, the graph is only for visualizing, the moderator is continuous, even if I have 'divided' it in the graph). How do I highlight this interaction that is happening (or that I'm suspecting that it will happen) at the mid-level of ideology? If I'm just saying
I hope my question is clear and not too stupid :-)
Just a bit of context to understand my research: Participants will either read a positive or a negative description of the situation in a country before colonialism. For those having a middle level of ideology (so they are neither in favor of it, nor totally against it), they will evaluate colonialism more positive when they have read a negative article about the time before colonialism than when they have read a positive article. Now I suspect ideology to moderate this effect, when it's either on a low or a high level. For example, I suspect that participants with a high level of ideology will contest the article if it talks positively about the past (the past BEFORE the colonisation began). As a result, they will evaluate the colonial past HIGHER than in the situation where they read a negative article (and vice versa for the ones with a low ideology). How can I voice this without 'categorizing' my continuous variable with terms as low, middle, high?