Visual illusions in geology
Examples of visual illusions in the laboratory are well documented, but what about illusions that occur during field observation of geological structures? In this article I discuss a study involving geologists and non-geologists and define some of the problems that may arise during geological field and laboratory work.
Framing bias: The effect of figure presentation on seismic interpretation
AbstractInterpreters of reflection seismic data generally use images to disseminate the outcomes of their geologic interpretation work. The presentation of such interpretation images can generate unwanted biases in the perception of the observers, an effect known as “framing bias.” These framing biases can enhance or reduce the confidence of the observer in the presented interpretation, independently of the quality of the seismic data or the geologic interpretation. We have tested the effect of presentation on confidence in interpretation of 761 participants of an online experiment. Experiment participants were presented with seismic images and interpretations, deliberately modified in different aspects to introduce potential framing biases. Statistical analysis of the results indicates that the image presentation had a subdued effect on participants’ confidence compared with the quality of the seismic data and interpretation. The results allow us to propose recommendations to minimize biases in the obser...
Evaluation and Control of Collapsible Soils
Some compacted soils wetted under certain conditions of compaction and loading may exhibit additional settlement (collapse). To investigate the effect of the soil type, compaction water content, initial dry unit weight and applied pressure at wetting on collapse potential, 138 single‐oedometer tests were conducted on eight different soils. The results indicate that well‐graded soils tend to collapse more than poorly graded ones under similar conditions. Furthermore, collapse potential decreases with an increase in (1) The difference between the sand and clay percentages; (2) compaction water content; and (3) initial dry unit weight, while it increases with pressure at wetting. A multiple regression analysis was performed on the laboratory results to provide a collapse‐predictive model that was substantiated by data reported by several researchers. A chart is presented to estimate (1) The collapse potential of soils under various conditions; and (2) the critical water content beyond which no collapse is ex...