# Health Misinformation in Social Networks: A Survey of Information Technology Approaches
## 3 Fact-Checking  
In this section, we examine the concept of fact-checking, its historical role in journalism, and its growing relevance across diverse fields such as social media and scientific research. We delve into various fact-checking approaches, including manual methods--whether expert- or crowd-sourced--and automated techniques that identify and validate claims using sophisticated algorithms and comprehensive knowledge bases. This section concludes with a list and discussion of available online fact-checking tools.  
Fact-checking is the process of verifying the factual accuracy of statements/claims. Historically, it has been associated with journalism, being an important process of media companies for verifying published information related to different types of claims (political, religious, social, etc.). The process of fact-checking is usually conducted either internally, using resources of the media company or through an external third party [1].  
In a similar manner, there is a verification and validation process of academic work in the scientific community, where the critical study of the prior literature, the soundness of the proposed approaches and methodologies, and the reproducibility and verifiability of the results are integral to academic research. However, the rise of==in algorithmically generated papers and fraudulent publications, as highlighted in [31] that studies the prevalence of nonsensical algorithmically generated papers in the scientific literature, and in [32] that assesses the retracted papers from cancer journals associated with \"paper mills\", underscores the challenges in maintaining scientific integrity. These works discuss fraud detection in scientific content, which parallels the challenge of spotting fake medical misinformation in social networks and the need for automated approaches.  
During the 2016 US elections, online media platforms were found susceptible to disseminating disinformation and misinformation [33]. This made fact-checking a hot topic across the scientific community, journalists, and online social users. This trend was further amplified due to the pandemic misinformation. As a result, the number and size of fact-checking organizations have grown across the globe and social platforms have started to develop partnerships with them [1]. In addition, the need for cutting-edge and credible scientific knowledge has made the scientific literature part of the fact-checking sources.  
Publishing fact-checked information has a positive effect on correcting false and inaccurate information, discouraging bad actors from spreading misinformation. However, the fact-checked information does not necessarily prevail due to the persistent promotion of less accurate claims from highly influential groups [34]. The same is also true for the medical domain, where the decrease in COVID-19 misperceptions thanks to fact-checkingdoes not persist over time even after repeated exposure [35]. As a result, fact-checked information is only part of the solution toward credible medical information, and it should be combined with the automatic fake news detection and mitigation approaches discussed in the next sections to be effective.  
The process of fact-checking is either performed manually, by domain experts or workers in crowdsourcing platforms, or automatically. The two approaches are discussed in detail below, while a detailed description of the available online fact-checking tools is provided afterward.