# Research on Factors Affecting Solvers' Participation Time in Online Crowdsourcing Contests
## 1 Introduction  
Crowdsourcing is the act of an enterprise that outsources the work traditionally performed by internal employees through an online public call to an uncertain group of people without clear boundaries [1]. Crowdsourcing contests are one of the most popular and effective crowdsourcing models [2]. A crowdsourcing contest mainly consists of three elements, as follows: Seekers, solvers, and the intermediary platform. The typical process is that a seeker sets the task requirements through the crowdsourcing platform and the solvers choose to participate and submit the solutions according to their own skills and knowledge. Then, the solver who provides the best solution will win the rewards [3]. There are some famous crowdsourcing platforms such as InnoCentive.com and Kaggle.com from the U.S., as well as Taskcn.com and ZBJ.com from China, etc. In a crowdsourcing contest, any participant can submit a task solution, but usually only the participant who provides the highest quality solution will win (i.e., winner take all) [4]. The performance of a crowdsourcing contest mainly depends on the solvers' active participation and effort. The solvers are completely voluntarily involved in the crowdsourcing contest andwhether the solvers actively participate in the contest is crucial to the survival of the crowdsourcing platform [5]. In the extant research, the main indicators to measure the performance of a crowdsourcing contest are the following: The number of submissions, the average quality of submissions, and the quality of the winning submission [6]. [PERSON] et al. [7] used the number of submissions to measure participants' behavior and concluded that a crowdsourcing contest that has higher rewards, a longer duration, a shorter description, a lower time cost, and a higher popularity will attract more solvers. [PERSON] et al. [8] believe that the higher the winning bidder's rating, the more likely the bidder is to propose an optimal solution. [PERSON] et al. [9] argued that the quality of the best creative ideas is determined by four factors including the average quality of ideas generated, the number of ideas generated, the variance in the quality of ideas generated, and the ability of the group to discern the quality of the ideas. [PERSON] and [PERSON] [10] used the average quality of solutions and the number of solutions to measure the performance of a crowdsourcing contest and they examined the impact of rewards, duration, and the length of task description on the performance of the crowdsourcing contest. They found that the quantity and quality of solutions were affected by different types of external factors. So, if seekers try to maximize the quantity and quality of solutions by increasing task rewards, some conflicts may arise and the quantity and quality goals cannot be achieved at the same time. The seekers' purpose in online crowdsourcing contests is to attract high-quality solutions and to obtain good and diverse solutions, which not only depends on task design but also on the seekers' understanding of the motivation and behavior of the solvers. The effort invested by a solver determines the quality of his/her solution and, then, the quality of his/her solution will have an impact on the probability of his/her winning. So, the participation effort is significantly related to the probability of winning. Usually, the level of participation effort can be measured objectively by participation time. Some researchers regard participation time as an independent variable in order to examine its impact on the probability of winning of a solver. [PERSON] et al. [11] found that the longer the time interval between registration and submission, the higher the chance of winning. [PERSON] et al. [12] believe that winning a solution depends on the solver's time investment and familiarity with the task. [PERSON] et al. [13] measured the solvers' participation behavior in three dimensions of solvers, the location where the solver first submitted, number of solvers, and solvers' participation time.