Figure 3: The State of the Evidence on a Fictitious Topic

see also: Main Story | Figure 1: ASHA's LOE System 

The hypothetical LOE table summarizes the quality of evidence and the types of research questions that have been addressed. In a systematic review, a table such as this will include every individual study contained in that review. This particular example indicates that a number of high-quality efficacy studies have been conducted. One might then conclude that research priorities should include an emphasis on well-designed effectiveness research, as there might be little to be gained from additional exploratory or efficacy research related to the same question.