A half-truth is a deceptive statement that includes some element of truth. The statement might be partly true, the statement may be totally true, but only part of the whole truth, or it may use some deceptive element, such as improper punctuation, or double meaning, especially if the intent is to deceive, evade, blame or misrepresent the truth. The purpose and or consequence of a half-truth is to make something that is really only a belief appear to be knowledge, or a truthful statement to represent the whole truth or possibly lead to a false conclusion. The order in which the true and false information is presented in a "half-truth" can make a difference in ultimate believability. Barchetti and colleagues show that when two unrelated statements are but together with syntax that suggests causality, the statement is believed if the premise is true (even if the conclusion is unrelated or false). Conversely, if the false statement is placed in the premise, the combined statement is less likely to be believed. Thus order of presentation can influence the credibility of a half-true statement and has been named the half-truth effect. According to the justified true belief theory of knowledge, in order to know that a given proposition is true, one must not only believe in the relevant true proposition, but one must also have a good reason for doing so. A half-truth deceives the recipient by presenting something believable and using those aspects of the statement that can be shown to be true as a good reason to believe the statement is true in its entirety, or that the statement represents the whole truth. A person deceived by a half-truth considers the proposition to be knowledge and acts accordingly. In January 2018, U.S. President Donald Trump claimed on Twitter that "because of my policies, Black Unemployment has just been reported to be at the LOWEST RATE EVER RECORDED!" Although the unemployment rate for black Americans was indeed at a record low, the rate had been consistently decreasing since 2010, seven years before Trump took office.