1 Final draft – forthcoming in Perspectives on Science Privacy, Informed Consent, and Participant Observation Julie Zahle – juliezahle@gmail.com Abstract: In this paper, I begin by detailing how social researchers may use informed consent to protect the situational and informational privacy of those they study while gathering data by way of the method of participant observation. Next, I argue that the principle of informed consent should not be regarded as an absolute demand: under specified conditions, it is acceptable to make an exception to the principle. Finally, I demonstrate that the employment of informed consent does not suffice to protect individuals’ privacy: social researchers must take a number of additional measures to prevent privacy invasions from occurring. 1. Introduction In the literature on social research, adherence to the principle of informed consent is sometimes recommended on the ground that the privacy of those being studied is hereby protected (see, e.g., Kelman 1977; Sieber 1992, p. 9; Hammersley and Traianou 2012, p. 114ff). The principle has it that before becoming part of a study, a competent individual must receive information about its purpose, use, etc., and on this basis freely agree to participate. Joan Sieber motivates the employment of informed consent as a way to safeguard research participants’ privacy as follows: “A research experience regarded by some as a delightful opportunity for self-disclosure could constitute an unbearable invasion of privacy for others. Informed consent is an important way to respect these individual differences […] One who considers a given research procedure an invasion of privacy can simply decline to participate” (Sieber, 1992, p. 49). In this paper, I examine in depth the proposal that social researchers should abide by the principle of informed consent in order to protect the privacy of those they study. More precisely, I consider this suggestion in the context of data generation by way of participant observation – a qualitative method that is widely used in the social sciences and humanities. Surprisingly, no comprehensive analysis along these lines has been offered so far whether by philosophers or social researchers. I start by introducing the method of participant observation. Next, I argue that there are two main ways in which a social researcher may intrude on individuals’ privacy when generating data by way of this method: she may invade research participants’ situational and informational privacy. On this basis, I present the principle of informed consent and show how to specify its conditions of application in order to tailor it to the protection of individuals’ situational and informational privacy. In the remainder of the paper, I take it that a participant observer should indeed make use of informed consent so as to safeguard research participants’ privacy. This contention raises two issues. The first is whether the principle of informed consent should be embraced as an absolute principle, that is, a principle without exceptions. I show that when certain conditions are met, the participant observer may make an exception to the principle and hereby set to a side the privacy protection that the principle offers. The other issue is whether the employment of informed consent is sufficient to protect research participants’ situational and informational privacy. I draw attention to three circumstances in which the participant observer needs to take further measures in order to prevent privacy invasions from occurring while she generates her data. Moreover, I discuss what these supplementary measures are. In the literature on social research, two further ways in which to protect research participants’ privacy are commonly mentioned too. Both of them deal with different aspects of treating collected data