Begin your conclusion with a summary statement that references your thesis. Don't use the same words you used in your thesis statement, reinforce the purpose of your paper by finding a new way of phrasing the idea. APA conclusions address your analysis of your research, if it coincides with pre-established ideas and your reasons for arriving at your thesis. These points make it easy for the reader to agree with your statement. Don't dilute your paper by adding new information in the conclusion. This information must be referred to in your introduction and explained in your body paragraphs. Think of your paper as a play -- it will only confuse the audience if you introduce new characters at the end.
The compelling element of an APA conclusion comes from stating your opinion and backing it up with exhaustive research. Strong APA endings also write to the intended audience. Consider any counterarguments and address them. The more detail and evidence you provide, the more likely it is that your reader will think your argument is sound. Create your own summary rather than relying on a quote to sum up your paper. Use quotes only to expand on a previous thought. Discuss how it encapsulates your thoughts on your research. This will validate your summary's point of view.
APA conclusions interpret the thesis by pointing out its many applications regarding the overall subject. Even in formal papers, the conclusion is where you can show your opinion about the significance of the denouement you have arrived at. Give your conclusion relevance by tying it into current events or a topical issue and illustrate the usefulness of your thesis in a wider aspect. Use APA-emphasized evidence such as statistics, facts and data to show what further steps can be taken or how your thesis fits into a larger issue.
APA style discourages the use of slang and encourages spelling out words rather than using a contraction. Use active sentences in your conclusion to state facts. When referring to someone's writing, use the simple past term "Hawking wrote" rather than "Hawking says". Don't use informal summary statements such as "So you see that..." which detract from the authoritative tone used in formal academic papers. The emphasis of an APA conclusion is on objectivity and paying close attention to your language. These are the keys to a convincing and effective conclusion.