If it is about self assessment, I don't think you need to go very far. Of course, it depends on what you want to present to the respondents, but usually for self assessments it is enough to use what the Expression Manager offers.
Usually you want to calculate some assessment value and based on that you want to show a text or an image or something. This can be done with expression manager.
Here a couple of links that you should have a look at:
www.limesurvey.org/manual/Expression_Manager
www.limesurvey.org/manual/ExpressionScript_examples
www.limesurvey.org/manual/Expression_Manager_sample_surveys
The first link gives you a general idea of what Expression Manager is and what it can do.
Then there are examples and even sample surveys.
How does this generally work?
You create one or several equation questions that will calculate the results and then use one or several text display questions to show your respondents the results.
Without knowing what you want to calculate and how you want to show it, there can't be said much more at this point.