We located six studies in health education that evaluated the effects of pictures with text on comprehension of health information. Comprehension is the process of interpreting the meaning of words or pictures to understand their collective meaning. It is different from recall which is the process of retrieving individual words or picture elements from memory. People may remember information without, necessarily, understanding it. Therefore, for a study to qualify as evaluating comprehension, the outcome measure had to go beyond simple recall and ask respondents to explain or do something with the information did find several studies that purported to assess comprehen- sion but, in fact, studied recall since they only asked respondents.
