Posted by Grant Richardson, 13th June, 2015
“In conclusion,” shows that you wish to use what you have written earlier to make a statement which you have not yet made.
Therefore, you would use it for a “discuss both views” essay.
“In summary,” shows you wish to rephrase or reiterate what you have already stated earlier (in the introduction and/or body paragraphs) as a more concise statement.
Therefore, you would use it in a “agree or disagree” essay, or a “two-part question” essay