Animal deception and the content of signals.

In cases of animal mimicry, the receiver of the signal learns the truth that he is either dealing with the real thing or with a mimic. Thus, despite being a prototypical example of animal deception, mimicry does not seem to qualify as deception on the traditional definition, since the receiver is not actually misled. We offer a new account of propositional content in sender-receiver games that explains how the receiver is misled (and deceived) by mimicry. We show that previous accounts of deception, and of propositional content, give incorrect results about whether certain signals are deceptive.

The Epistemic Threat of Deepfakes.

Deepfakes are realistic videos created using new machine learning techniques rather than traditional photographic means. They tend to depict people saying and doing things that they did not actually say or do. In the news media and the blogosphere, the worry has been raised that, as a result of deepfakes, we are heading toward an "infopocalypse" where we cannot tell what is real from what is not. Several philosophers (e.g., Deborah Johnson, Luciano Floridi, Regina Rini) have now issued similar warnings. In this paper, I offer an analysis of why deepfakes are such a serious threat to knowledge. Utilizing the account of information carrying recently developed by Brian Skyrms (2010), I argue that deepfakes reduce the amount of information that videos carry to viewers. I conclude by drawing some implications of this analysis for addressing the epistemic threat of deepfakes.

Shedding Light on Keeping People in the Dark.

We want to keep hackers in the dark about our passwords and our credit card numbers. We want to keep potential eavesdroppers in the dark about our private communications with friends and business associates. This need for secrecy raises important questions in epistemology (how do we do it?) and in ethics (should we do it?). In order to answer these questions, it would be useful to have a good understanding of the concept of keeping someone in the dark. Several philosophers (e.g., Bok, 1983; Carson, 2010; Mahon, 2009; Scheppele, 1988) have analyzed this concept (or, equivalently, the concept of keeping secrets) in terms of concealing and/or withholding information. However, their analyses incorrectly exclude clear instances of keeping someone in the dark. And more important, they incorrectly focus on possible means of keeping someone in the dark rather than on what it is to keep someone in the dark. In this paper, I argue that you keep X in the dark about a proposition P if and only if you intentionally cause X not to have a true belief that P. In addition, I show how this analysis of keeping someone in the dark can be extended from a categorical belief model of epistemic states to a credence (or degree of belief) model.

Consumer health information on the Internet about carpal tunnel syndrome: indicators of accuracy.

PURPOSE: To identify indicators of accuracy for consumer health information on the Internet. METHODS: Several popular search engines were used to find websites on carpal tunnel syndrome. The accuracy and completeness of these sites were determined by orthopedic surgeons. It also was noted whether proposed indicators of accuracy were present. The correlation between proposed indicators of accuracy and the actual accuracy of the sites was calculated. RESULTS: A total of 116 websites and 29 candidate indicators were examined. A high Google toolbar rating of the main page of a site, many inlinks to the main page of a site, and an unbiased presentation of information on carpal tunnel syndrome were considered genuine indicators of accuracy. Many proposed indicators taken from published guidelines did not indicate accuracy (e.g., the author or sponsor having medical credentials). CONCLUSION: There are genuine indicators of the accuracy of health information on the Internet. Determining these indicators, and informing providers and consumers of health information about them, would be useful for public health care. Published guidelines have proposed many indicators that are obvious to unaided observation by the consumer. However, indicators that make use of the invisible link structure of the Internet are more reliable guides to accurate information on carpal tunnel syndrome.

Indicators of accuracy of consumer health information on the Internet: a study of indicators relating to information for managing fever in children in the home.

OBJECTIVES: To identify indicators of accuracy for consumer health information on the Internet. The results will help lay people distinguish accurate from inaccurate health information on the Internet. DESIGN: Several popular search engines (Yahoo, AltaVista, and Google) were used to find Web pages on the treatment of fever in children. The accuracy and completeness of these Web pages was determined by comparing their content with that of an instrument developed from authoritative sources on treating fever in children. The presence on these Web pages of a number of proposed indicators of accuracy, taken from published guidelines for evaluating the quality of health information on the Internet, was noted. MAIN OUTCOME MEASURES: Correlation between the accuracy of Web pages on treating fever in children and the presence of proposed indicators of accuracy on these pages. Likelihood ratios for the presence (and absence) of these proposed indicators. RESULTS: One hundred Web pages were identified and characterized as "more accurate" or "less accurate." Three indicators correlated with accuracy: displaying the HONcode logo, having an organization domain, and displaying a copyright. Many proposed indicators taken from published guidelines did not correlate with accuracy (e.g., the author being identified and the author having medical credentials) or inaccuracy (e.g., lack of currency and advertising). CONCLUSIONS: This method provides a systematic way of identifying indicators that are correlated with the accuracy (or inaccuracy) of health information on the Internet. Three such indicators have been identified in this study. Identifying such indicators and informing the providers and consumers of health information about them would be valuable for public health care.