Documents that consist of a series of unsupported assertions amount to little more than a request for the reader’s trust. Even when the writer is eminently trustworthy, most readers find such documents easy to dismiss. In contrast, providing evidence to support your assertions increases the likelihood that your readers will accept your main point. Note the differences between the following passages.

Unsupported Assertion

Supported Assertion

Similarly, visual sources can lend support to an assertion. An assertion about the unintended consequences of military action, for example, might be accompanied by a photograph of a war-torn street or a wounded child.