Expectation bias in applied ethology: debiasing techniques and opinion of ethologists

There is increasing evidence that the field of applied ethology is prone to expectation biases invalidating research outcomes. Nevertheless, outcome assessors are rarely blinded. We surveyed delegates of the International Society for Applied Ethology (ISAE) 2014 congress shortly before (n=39 respondents) and after (n=51 respondents) a combined congress plenary lecture and workshop on expectation bias in applied ethology. The aims were to evaluate the effect of the plenary lecture and workshop on the opinion of applied ethologists and to better comprehend why blinding outcome assessors seems so rarely practiced as a debiasing technique in this field of research. A limited awareness about expectancy effects among ethologists and the logistic constraints of blinded observations rather than a perceived low susceptibility of the research field seems the larger part of the explanation. Awareness about expectancy effects and debiasing techniques was higher immediately after than before the congress plenary lecture and workshop. For example, research situations considered as most susceptible to expectation bias – i.e. when the data-collector uses subjective methods and has strong expectations about the research outcome - were perceived to be more common in applied ethology than in other scientific disciplines (29.8% versus 16.9%, P<0.001). Moreover, non-blinded data collection in such research situations was viewed more disapprovingly after the plenary lecture and workshop as compared to before (lsmean of 6.8 versus 7.8 on a 10-point Likert scale, P<0.05). In addition to the immediate effect of the plenary lecture and workshop, a more sustained and concerted effort seems needed throughout all stages of the research process to avoid expectation bias invalidating research findings and to improve the scientific credibility of the field of applied ethology.