## 2 Related Work  
### Crowdsourcing and Collective Intelligence  
Crowdsourcing is a portmanteau to describe how businesses use the Internet to outsource work to the crowd. After studying more than 40 definitions of crowdsourcing in the scientific and popular literature, [PERSON] and [PERSON] [PERSON] and [PERSON] (2018) summarized crowdsourcing as a type of participative online activity in which a party proposes to the public via a flexible open call the voluntary undertaking of a task. Crowdsourcing in the modern conception is an information technology (IT)-mediated phenomenon, meaning that a form of IT is always used to create and access crowds of people (2019). Members of the public submit their work, money, knowledge, and/or experience to the initiating party and are compensated with monetary prizes or with recognition of their contribution. Usually the crowdsourced result is given back to the public as a kind of response, especially when there no monetary compensation is involved (2020). By properly using a crowdsourcing method, one can manage large jobs with thousands of workers or do small jobs that require just a single person. According to the problem being solved, crowdsourcing can be classified into following four types (2018):  
* Crowdscontests: A party tasks a crowd with proposing ideas about a given topic, for example, logo design, software testing, or other creative projects. This type of crowdsourcing can identify the best worker for a given job, as many people are proposing or creating items. The initiating party rewards only a single contributor. * Macrotasks: A party tasks a crowd with a specific job, for example, software application development or thesis editing. The initiating party selects only one person/team to carry out the entire job, and the hired party is compensated for the task. * Microtasks: A party tasks a crowd with many small units of a job that are a part of a larger and more complicated project that typically requires a large workforce: for example, tagging a million photos or transcribing many medical records. These small jobs may or may not require human intelligence. All contributors are given recognition as a kind of reward. * Crowdfunding: In contrast to the three types mentioned above, crowdfunding requires a monetary contribution from the crowd. This has been a very popular approach to raise money through social networks, especially for startup companies or innovative ideas that need money to realize them. Contributors can receive goods or services or they can give money as a donation. The crowdsourcing work involved in this research is a type of microtask. In order to compensate for the lack of an adequate fire inspection workforce, the key point in this study is to hire the crowd to inspect many commercial and public buildings against fire safety-related requirements. In this case, the huge job of inspecting many buildings at more frequent intervals is divided into many small tasks of inspecting only one or two items in a given building. This makes a seemingly impossible goal more achievable. To accomplish the crowdsourcing, there is a need to create a platform that can engage interested people to participate in the fire inspection process. Contributors can be compensated by cash (if the initiating party has a budget) or by acknowledgement (or any other in-kind offering). Collective intelligence (CI), known as the wisdom of the crowd, refers to the collective opinion of a group of individuals rather than that of a single expert [22]. Crowdsourcing usually generates CI, which provides better results than can be achieved by hiring one or a few experts. A typical example is Wikipedia, an online, collaboratively created, and maintained encyclopedia--for this type of project, it is impossible to achieve the desired quality in a traditional editing paradigm [23]. CI is not new to the Information Age, but the rapid expansion of mobile Internet has largely facilitated the development of social information sites that rely on collective human knowledge, such as Yahoo!