The social psychology of perception experiments: Hills, backpacks, glucose, and the problem of generalizability.

Abstract

Experiments take place in a physical environment but also a social environment. Generalizability from experimental manipulations to more typical contexts may be limited by violations of ecological validity with respect to either the physical or the social environment. A replication and extension of a recent study (a blood glucose manipulation) was conducted to investigate the effects of experimental demand (a social artifact) on participant behaviors judging the geographical slant of a large-scale outdoor hill. Three different assessments of experimental demand indicate that even when the physical environment is naturalistic, and the goal of the main experimental manipulation was primarily concealed, artificial aspects of the social environment (such as an explicit requirement to wear a heavy backpack while estimating the slant of a hill) may still be primarily responsible for altered judgments of hill orientation.

How Relevant are Incidental Power Poses for HCI?

“…It is however still unclear whether "this effect is a methodological artifact or meaningful" [17]: demand characteristics are an alternative explanation for the effect, that is, participants' responses could be due to the context of the experiment during which they are explicitly instructed to take on certain postures, which may suggest to participants that these postures must be a meaningful experimental manipulation. Such demand characteristics have previously been shown to be explanatory for an earlier finding claiming that people wearing a heavy backpack perceive hills as steeper (see Bhalla and Proffitt [3] for the original study and Durgin et al [27] for an extended study showing that the effect can be attributed to demand characteristics).…”

Perceived difficulty of a motor task affects memory but not action

“…The Durgin et al (2009) result has been criticized because the slope to be estimated was of a short board rather than a long hill that would require a significant effort to be scaled (Proffitt, 2009). Recently, however, Durgin et al (2012) extended their result to a real hill, with similar results. The fact that only one of our participants guessed the true purpose of the experiment in our postexperiment questionnaire indicates that response bias based on the participants' expected outcome could not have affected their judgments.…”

Multimodally specified energy expenditure and action-based distance judgments

“…They told participants not to overthink the task, but to comply with a similar strategy of stopping when it felt as if they had traveled to the target location. Durgin et al (2009;Durgin et al, 2012) and Woods, Philbeck, and Danoff (2009) have criticized the methodology of several of Proffitt's studies about the influence of energetic variables on verbal reports of perceived distance, concluding that the results may reflect response bias rather than a change in perception. Proffitt (2009Proffitt ( , 2013 has acknowledged that it is still uncertain whether or when response bias may play a role in such results, but a proper avenue of research to continue this line should have manipulations that are not intuitive to participants, such as the gait symmetry manipulation in White (2012).…”

“…Energy expenditure influences prospective (verbal) distance reports even when environmental (i.e., optical) cues remain constant (Proffitt et al, 2003;Witt, Proffitt, & Epstein, 2004). Although these claims have stirred controversy (Durgin, Baird, Greenburg, Russell, Shaughnessy, & Waymouth, 2009;Durgin, Klein, Spiegel, Strawser, & Williams, 2012;Proffitt, Stefanucci, Banton, & Epstein, 2006;Proffitt & Zadra, 2011;Zadra, Schnall, Weltman, & Proffitt, 2010), not all of the findings can be attributed to response bias or artifacts (Witt & Proffitt, 2008;Witt, Schuck, & Taylor, 2011). The metabolic cost of a future action appears to influence how perceivers apprehend the environment's spatial layout.…”