An evaluation of visual and verbal based standards for landscape assessment

Existing verbal standards accepted in visual resource management (U.S.D.A. Forest Service, 1975 and U.S.D.I., Bureau of Land Management, 1980) as a reference for evaluating the landscape have certain shortcomings. One hypothesis is that visual images of the landscape which are used as a basis or standard along with landscape descriptions for measuring different levels or categories of a landscape attribute (visual standards) will produce more consistent ratings than using verbal standards. The purpose of this thesis is to examine the use of visual standards as a predictive tool to improve landscape assessment. This study involved the development of visual standards and a comparative survey study. One group of survey respondents was asked to rate or evaluate selected landscape variables (complexity and vividness) for a set of 15 landscape scenes. Another group used more traditional verbal standards to evaluate the same variables for the same landscape scenes. The effects of visual standards was compared with the effect of verbal standards on (1) assessing the landscape; (2) people’s attitudes toward landscape ratings; and (3) people’s attitudes toward the rating process. The findings indicate that using visual standards cannot produce more consistent results for rating landscape variables. Further research needs to be conducted for excluding the external variables which may affect the quality of visual standards. In fact, there is evidence to suggest that visual standards are perceived by the user as a more accurate reference. The findings also indicate that using visual standards result in a broader use of the rating scale particularly at the lower end of the scale and cause lower rating results for the tested scenes compared to verbal standards. Although using visual standards to access complexity and vividness cannot improve their predictive relationship to preference, the past research indicating a strong relationship between landscape complexity and visual quality may be influenced or biased by people’s preference for the landscape. In terms of the use of image based visual standards in computer application, this limited research has been unable to find any clear advantages in terms or reliability or validity. However, visual standards do not appear to be any less reliable and valid than verbal standards.