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Title: Predicting the Working Time of Microtasks Based on Workers' Perception of Prediction Errors
Crowd workers struggle to earn adequate wages. Given the limited task-related information provided on crowd platforms, workers often fail to estimate how long it would take to complete certain microtasks. Although there exist a few third-party tools and online communities that provide estimates of working times, such information is limited to microtasks that have been previously completed by other workers, and such tasks are usually booked immediately by experienced workers. This paper presents a computational technique for predicting microtask working times (i.e., how much time it takes to complete microtasks) based on past experiences of workers regarding similar tasks. The following two challenges were addressed during development of the proposed predictive model — (i) collection of sufficient training data labeled with accurate working times, and (ii) evaluation and optimization of the prediction model. The paper first describes how 7,303 microtask submission data records were collected using a web browser extension — installed by 83 Amazon Mechanical Turk (AMT) workers — created for characterization of the diversity of worker behavior to facilitate accurate recording of working times. Next, challenges encountered in defining evaluation and/or objective functions have been described based on the tolerance demonstrated by workers with regard to prediction errors. To this end, surveys were conducted in AMT asking workers how they felt regarding prediction errors in working times pertaining to microtasks simulated using an “imaginary” AI system. Based on 91,060 survey responses submitted by 875 workers, objective/evaluation functions were derived for use in the prediction model to reflect whether or not the calculated prediction errors would be tolerated by workers. Evaluation results based on worker perceptions of prediction errors revealed that the proposed model was capable of predicting worker-tolerable working times in 73.6% of all tested microtask cases. Further, the derived objective function contributed to realization of accurate predictions across microtasks with more diverse durations.  more » « less
Award ID(s):
1928631
NSF-PAR ID:
10192272
Author(s) / Creator(s):
Date Published:
Journal Name:
Human computation
Volume:
6
Issue:
1
ISSN:
2330-8001
Page Range / eLocation ID:
192-219
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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In dedicated spots in the notebook, participants could write custom pre-processing code, machine learning models, and post-processing algorithms. The starter kit provided instant feedback about participants' custom routines through data visualisations. Using the notebook only, teams were able to run the code on WML, making use of a compute cluster of IBM's resources. The starter kit also enabled submission of the final code to a data storage to which only the challenge team had access. (4) Watson Machine Learning provided access to shared compute resources (GPUs). Code was bundled up automatically in the starter kit and deployed to and run on WML. WML in turn had access to shared storage from which it requested recorded data and to which it stored the participant's code and trained models. (5) IBM's Cloud Object Storage held the data for this challenge. Using the starter kit, participants could investigate their results as well as data samples in order to better design custom algorithms. (6) Utility Functions were loaded into the starter kit at instantiation. This set of functions included code to pre-process data into a more common format, to optimise streaming through the use of the NutsFlow and NutsML libraries [10], and to provide seamless access to the all IBM services used. Not captured in the diagram is the final code evaluation, which was conducted in an automated way as soon as code was submitted though the starter kit, minimising the burden on the challenge organising team. Figure 1: High-level architecture of the challenge platform Measuring success The competitive phase of the "Deep Learning Epilepsy Detection Challenge" ran for 6 months. Twenty-five teams, with a total number of 87 scientists and software engineers from 14 global locations participated. All participants made use of the starter kit we provided and ran algorithms on IBM's infrastructure WML. Seven teams persisted until the end of the challenge and submitted final solutions. The best performing solutions reached seizure detection performances which allow to reduce hundred-fold the time eliptologists need to annotate continuous EEG recordings. Thus, we expect the developed algorithms to aid in the diagnosis of epilepsy by significantly shortening manual labelling time. Detailed results are currently in preparation for publication. Equally important to solving the scientific challenge, however, was to understand whether we managed to encourage participation from non-expert data scientists. Figure 2: Primary occupation as reported by challenge participants Out of the 40 participants for whom we have occupational information, 23 reported Data Science or AI as their main job description, 11 reported being a Software Engineer, and 2 people had expertise in Neuroscience. Figure 2 shows that participants had a variety of specialisations, including some that are in no way related to data science, software engineering, or neuroscience. No participant had deep knowledge and experience in data science, software engineering and neuroscience. Conclusion Given the growing complexity of data science problems and increasing dataset sizes, in order to solve these problems, it is imperative to enable collaboration between people with differences in expertise with a focus on inclusiveness and having a low barrier of entry. We designed, implemented, and tested a challenge platform to address exactly this. Using our platform, we ran a deep-learning challenge for epileptic seizure detection. 87 IBM employees from several business units including but not limited to IBM Research with a variety of skills, including sales and design, participated in this highly technical challenge. 
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