# Research on Factors Affecting Solvers' Participation Time in Online Crowdsourcing Contests
## 3 Development of Hypotheses  
According to the literature review above, it is believed that the factors affecting solvers' participation time include task design, task description, task process, and environmental factors. We constructed an affecting model of participation time and the affecting mechanism is in Figure 1.  
Participation time indicates the time invested by a solver in the completion of the task, which reflects the effort of solvers who chose to participate in the task. The task rewards not only affect the number of submissions, but also affect the level of effort expended by the solvers after choosing to participate. The expected value theory is mainly used in research to explain the effects of task rewards on solvers' participation. [PERSON] (2018) summarizes expected value as a function of expectations, media, and value. He thought that a higher probability of winning contributes to a higher expected value, which will increase the participation motivation of solvers and attract them to expend more participation effort. So, in order to improve their expected value, the solver who participates in a crowdsourcing contest will invest more time and energy to improve the quality of solution and increase the attention to the task, so as to increase the probability of receiving monetary rewards. In another way, increasing task rewards will further incentivize solvers' motivation and strengthen the participation effort of solvers [14]. Solvers have an extrinsic motivation to pursue higher economic returns, which drives the solvers to continue to focus on the task and invest more time and energy [16]. Thus, we use participation time to indicate the degree of participation effort and believe that the solvers in the participation state will invest more time and cost to obtain higher expected returns by increasing the probability of successful biding. The participation time is the working time that the solver choses to participate in the task and expend his/her effort. The more the investment time, the greater the effort and the expected returns. So, we believe there is a positive linear relationship between participation time and task rewards and proposed the first Hypothesis 1a. **Hypothesis 1a. **_Task rewards have a positive impact on the solvers' participation time._  
Task duration is also an important factor that researchers focus on. According to the expected value theory, for solvers, the longer the task duration, the more time the solvers get to complete the task. Thereby, they can improve the quality of a solution to gain the expected value. Some studies have shown that longer task durations will result in better performance of crowdsourcing contests [10; 20]. The solver's participation in the crowdsourcing contest is a kind of trading behavior and his/her ultimate goal is to obtain the highest expected value at the lowest cost. Hence, to recover the input cost in the short term is one of the important factors for a rational solver to consider. For a task with a short duration, solvers can obtain the bidding result as soon as possible, can achieve the expected value with a certain probability, and this will contribute to cover solvers' cost in a short time. If the duration is too long, the participation cost will increase, so that the time for the successful bidder to obtain the task rewards becomes long and it will require solvers to expend more time and pay more attention. [PERSON] et al. [36] believe that a longer task duration will increase the workload of each solver, improve the quality of task solutions, and increase the return of the seeker. However, with the task duration increasing, solvers' participation will be decreased and in turn, the revenue of seekers will be discounted. Since, for solvers, a longer task duration means a longer cost-recovery period and rising opportunity cost, then the solver's patience will be eliminated which makes it unnecessary for him/her to invest too much time to complete a task with a lower expected value, his/her participation time is reduced.