03/04/2020 – Dylan Finch – Pull the Plug?

March 4, 2020 Dylan Finch 1 Comment

Word count: 596

Summary of the Reading

The main goal of this paper is to make image segmentation more efficient. Image segmentation as it is now, requires humans to help with the process. there are just some images that machines cannot segment on their own. However, there are many cases where an image segmentation algorithm can do all of the work on its own. This presents a problem: we do not know when we can use an algorithm and when we have to use a human, so we have to have humans review all of the segmentations. This is highly inefficient. This paper tries to solve this problem by introducing an algorithm that can decide when a human is required to segment an image. The process described in the paper involves scoring each segmented image done by machines, then giving humans the task of reviewing the lowest scoring images. Overall, the process was very effective and saved a lot of human effort.

Reflections and Connections

I think that this paper gives a great example of how humans and machines should interact, especially when it comes to humans and AIs interacting. Often times, we set out in research with the goal of creating a completely automated process that throws the human away and tries to create an AI or some other kind of machine that will do all of the work. This is often a very bad solution. AIs as they currently are, are not good enough to do most complex tasks all by themselves. In the cases of tasks like image segmentation, this is an especially big issue. These tasks are very easy for humans to do and very hard for AIs to do. So, it is good to see a researcher who is willing to use human strengths to make up for the weaknesses of machines. I think it is a good thing to have both things working together.

This paper also gives us some very important research, trying to answer the question of when we should machines and when we should use humans. This is a very tough question and it comes up in a lot of different fields. Humans are expensive, but machines are often imperfect. It can be very hard to decide when you should use one or the other. This paper does a great job of answering this question for image segmentation and I would love to see more similar research in other fields explain when it is best to use humans and machines in those fields.

While I like this paper, I do also worry that it is simply moving the problem, rather than actually solving it. Now, instead of needing to improve a segmentation algorithm, we need to improve the scoring algorithm for the segmentations. Have we really improved the solution or have we just moved the area that now needs further improvement?

Questions

How could this kind of technology be used in other fields? How can we more efficiently use human and machine strengths together?
In general, when do you think it is appropriate to create a system like this? When should we not fully rely on AI or machines?
Did this paper just move the problem, or do you think that this method is better than just creating a better image segmentation algorithm?
Does creating systems like this stifle innovation on the main problem?
Do you think machines will one day be good enough to segment images with no human input? How far off do you think that is?

3/4/20 – Jooyoung Whang – Toward Scalable Social Alt Text: Conversational Crowdsourcing as a Tool for Refining Vision-to-Language Technology for the Blind

March 4, 2020 Jooyoung Whang 1 Comment

In this paper, the authors study the effectiveness of vision-to-language systems for automatically generating alt texts for images and the impact of human-in-the-loop for this task. The authors set up four methods for generating alt text. First is a simple implementation of modern vision-to-language alt text generation. The second is a human-adjusted version of the first method. The third method is a more involved one, where a Blind or Vision Impaired (BVI) user chats with a non-BVI user to gain more context about an image. The final method is a generalized version of the third method, where the authors analyzed the patterns of questions asked during the third method to form a structured set of pre-defined questions that a crowdsource worker can directly provide the answer to without having the need for a lengthy conversation. The authors conclude that current vision-to-language techniques can, in fact, harm context understanding for BVI users, and simple human-in-the-loop methods significantly outperform. They also found that the method of the structured questions worked the best.

This was an interesting study that implicitly pointed out the limitation of computers at understanding social context which is a human affordance. The authors stated that the results of a vision-to-language system often confused the users because the system did not get the point. This made me wonder if the current limitation could be overcome in the future.

I was also concerned whether the authors’ proposed methods were even practical. Sure, the human-in-the-loop method involving Mturk workers greatly enhanced the description of a Twitter image, but based on their report, it’ll take too long to retrieve the description. The paper reports that to answer one of the structured questions, it takes on average, 1 minute. This is excluding the time it takes for a Mturk worker to accept a HIT. The authors suggested pre-generating alt texts for popular Tweets, but this does not completely solve the problem.

I was also skeptical about the way the authors performed validation with the 7 BVI users. In their validation, they simulated their third method (TweetTalk, a conversation between BVI and sighted users). However, they did not do it by using their application, but rather a face-to-face conversation between the researchers and the participants. The authors claimed that they tried to replicate the environment as much as possible, but I think there still can be flaws since the researchers serving as the sighted user already had expert knowledge about their experiment. Also, as stated in the paper’s limitations section, the validation was performed with too fewer participants. This may not fully capture the BVI users’ behaviors.

These are the questions that I had while reading this paper:

1. Do you think the authors’ proposed methods are actually practical? What could be done to make them practical if you don’t think so?

2. What do you think were the human affordances needed for the human element of this experiment other than social awareness?

3. Do you think the authors’ validation with the BVI users is sound? Also, the validation was only done for the third method. How can the validation be done for the rest of the methods?

03/04/2020 – Vikram Mohanty – Combining crowdsourcing and google street view to identify street-level accessibility problems

March 4, 2020 Vikram Mohanty Leave a comment

Authors: Kotaro Hara, Vicki Le, and Jon Froehlich

Summary

This paper discusses the feasibility of using AMT crowd workers to label sidewalk accessibility problems in Google Street View. The authors create ground truth datasets with the help of wheelchair users, and found that Turkers reached an accuracy of 81%. The paper also discusses some quality control and improvement methods, which was shown to be effective i.e. improved the accuracy to 93%.

Reflection

This paper reminded me of Jeff Bigham’s quote – “Discovery of important problems, mapping them onto computationally tractable solutions, collecting meaningful datasets, and designing interactions that make sense to people is where HCI and its inherent methodologies shine.” It’s a great example for two important things mentioned in the quote : a) discovery of important problems, and b) collecting meaningful datasets. The paper’s contribution mentions that the datasets collected will be used for building computer vision algorithms, and this paper’s workflow involves the potential end-users (wheelchair users) early on in the process. Further, the paper attempts to use Turkers to generate datasets that are comparable in quality to that of the wheelchair users, essentially setting a high quality standard for generating potential AI datasets. This is a desirable approach for training datasets, which can potentially help prevent problems in popular datasets as outlined here: https://www.excavating.ai/.

The paper also proposed two generalizable methods for improving data quality from Turkers. Filtering out low-quality workers during data collection by seeding in gold standard data may require designing modular workflows, but the time investment may well be worth it.

It’s great to see how this work evolved to now form the basis for Project Sidewalk, a live project where volunteers can map accessibility areas in the neighborhood.

Questions

What’s your usual process for gathering datasets? How is it different from this paper’s approach? Would you be willing to involve potential end-users in the process?
What would you do to ensure quality control in your AMT tasks?
Do you think collecting more fine-grained data for training CV algorithms will come at a trade-off for the interface not being simple enough for Turkers?

03/04/2020 – Nurendra Choudhary – Real-time captioning by groups of non-experts

March 4, 2020 Nurendra Choudhary 1 Comment

Summary

In this paper, the authors discuss a collaborative real-time captioning framework called LEGION:SCRIBE. They compare their system against the previous approach called CART and Automated Speech Recognition (ASR) system. The authors initiate the discussion with the benefits of captioning. They proceed to explain the expensive cost of hiring stenographers. Stenographers are the fastest and most accurate captioners with access to specialized keyboards and expertise in the area. However, they are prohibitively expensive (100-120$ an hour). ASR is much cheaper but their low accuracy deems them inapplicable in most real-world scenarios.

To alleviate the issues, the authors introduce SCRIBE framework. In SCRIBE, crowd-workers caption smaller parts of the speech. The parts are merged using an independent framework to form the final sentence. The latency of the system is 2.89s, emphasizing its real-time nature, which is a significant improvement over ~5s of CART.

Reflection

The paper introduces an interesting approach to collate data from multiple crowd workers for sequence learning tasks. The method has been applied before in cases such as Google Translate (translating small phrases) and ASR (voice recognition of speech segments). However, SCRIBE distinguishes itself by bringing in real-time improvement in the system. But, the system relies on the availability of crowd workers. This may lead to unreliable behaviour in the system. Additionally, the hired workers are not professionals. Hence, the quality is affected by human behavioral features such as mindset, emotions or mental stamina. I believe a study on the evolution of SCRIBE overtime and its dependence on such features needs to be analyzed.

Furthermore, I question the crowd management system. Amazon MT cannot guarantee real-time labourers. Currently, given the supply of workers with respect to the tasks, workers are always available. However, as more users adopt the system, this need not always hold true. So, crowd management systems should provide alternatives that guarantee such requirements. Also, the work provider needs to find alternatives to maintain real-time interaction, in case the crowd fails. In case of SCRIBE, the authors can append an ASR module in a situation of crowd failure. ASR may not give the best results but would be able to ensure smoother user experience.

The current development system does not consider the volatility of crowd management systems. This makes them an external single point of failure. I think there should be a push in the direction of simultaneously adopting multiple management systems for the framework to increase their reliability. This will also improve system efficiency because it has a more diverse set of results as choice. Thus benefiting the overall model structure and user adoption.

Questions

Google Translate uses a similar strategy by asking its users to translate parts of sentences. Can this technique be globally applied to any sequential learning framework? Is there a way we can divide sequences into independent segments? In case of dependent segments, can we just use a similar merging module or is it always problem-dependent?
The system depends on the availability of crowd workers. Should there be a study on the availability aspect? What kind of systems would be benefitted from this?
Should there be a new crowd work management system with a sole focus on providing real-time data provisions?
Should the responsibility of ensuring real-time nature be on the management system or the work provider? How will it impact the current development framework?

Word Count: 567

03/04/20 – Akshita Jha – Pull the Plug? Predicting If Computers or Humans Should Segment Images

March 4, 2020 Akshita Jha 1 Comment

Summary:
“Pull the Plug? Predicting If Computers or Humans Should Segment Images” by Gurari et. al. talks about image segmentation. They propose a resource allocation framework that tries to predict when best to use a computer for segmenting images and when to switch to humans. Image segmentation is the process of “partitioning a single image into multiple segments” in order to simplify the image into something that is easier to analyze. The authors implement two systems that decide when to replace humans with computers to create fine-grained segments and when to replace computers with humans in order to get coarse segments. They demonstrate through experiments that this mixed model of humans and computers beats the state of the art systems for image segmentation. The authors use the resource allocation framework, “Pull the Plug”, on humans or computers. They do this by giving the system an image and trying to predict if an annotation should from a human or a computer. The authors evaluate the model using Pearson’s correlation coefficient (CC) and mean absolute error (MAE). CC indicates the correlation strength of the predicted score to the actual scores given by the Jaccard index on the ground truth. MAE is the average prediction errors. The authors thoroughly experiment with initializing segmentation tools and reducing human effort initialization.

Reflections:
This is an interesting work that successfully makes uses of mixed modes involving both humans and computers to enrich the precision and accuracy of a task. The two methods that the authors design for segmenting an image was particularly thoughtful. First, given an image, the authors design a system that tries to predict whether the image requires fine-grained segmentation or coarse-grained segmentation. This is non-trivial as this task requires the system to possess a certain level of “intelligence”. The authors use segmentation tolls but the motivation of the system design is to remain agnostic to these particular segmentation tools. The systems rank several segmentation tools by using a tool designed by the authors to predict the quality of the segmentation. The system then allocates the available human budget to create coarse segmentations. The second system tries to capture whether an image requires fine-grained segmentation or not. They do this by building on the coarse segmentation given by the first system. The second system refines the segmentation and allocates the available human budget to create fine-grained segmentation for low predicted quality segmentations. Both these tasks rely on the system proposed by the authors to predict the quality of candidate segmentation.

Questions:
1. The authors rely on their proposed system of predicting the quality of candidate segmentations. What kind of errors do you expect?
2. Can you think of a way to improve this system?
3. Can we replace the segmentation quality prediction system with a human? Do you expect the system to improve or would the performance go down? How would it affect the overall experience of the system?
4. In most such systems, humans are needed only for annotation. Can we think of more creative ways to engage humans while improving the system performance?

Subil Abraham – 03/04/2020 – Real-time captioning by groups of non-experts

March 4, 2020 Subil Abraham Leave a comment

This paper pioneers the approach of using crowd work for closed captioning systems. The scenario they target is classes and lectures, where a student can hold up their phone and record the speaker and the sound the transmitted to the crowd workers. The sound that is passed is given as bite sized pieces for the crowd workers to transcribe, and the paper’s implementation of the multiple sequence alignment algorithms takes those transcriptions and combines them. The focus of the tool is very much on real-time captioning so the amount of time a crowd worker can spend on a portion of sound is limited. The authors design interfaces on the worker side to promote continuous transcription, and on the user side to allow them to correct the received transcriptions in real time, enhancing the quality further. The authors had to deal with interesting challenges in resolving errors in the transcription, which they did by a combination of comaparing transcriptions of the same section from different crowd workers, using bigram and trigram data to validate the word ordering. Evaluations showed that precision was stable while coverage increased with increase in the number of workers, while having lower error rate compared to automatic transcription and untrained transcribers.

One thing that needs to be pointed out about this work is that I believe that ASR is always rapidly improving and has made significant strides from when this paper was published. From my own anecdotal experience, Youtube’s automatic closed captions are getting very very close to being fully accurate (however, thinking back on our reading of the Ghost Work book at the beginning of the semester, I wonder if Youtube is cheating a bit and using crowd work intervention for some their videos to help their captioning AI along). I also find that the author’s solution for merging the transcriptions of the different sound bites is interesting. How they would solve that was the first thing that was on my mind because it was not going to be a matter of simply aligning the time stamps because those were definitely going to be imprecise. So I do like their clever multi part solution. Finally, I was a little surprised and disappointed that the WER was at ~45% which was a lot higher than I expected. I was expecting the error rate to be a lot closer to professional transcribers but unfortunately not. The software still has a way to go in that.

How could you get the error rate down to the professional transcriber’s level? What is going wrong there that is causing it to be that high?
It’s interesting to me that they couldn’t just play isolated sound clips but instead had to raise and lower volume on a continuous stream for better accuracy. Where are the other places humans work better when they have a continuous stream of data rather than discrete pieces of data?
Is there an ideal balance between choosing precision and coverage in the context of this paper? This was something that also came up in last week’s readings. Should the user decide what the balance should be? How would they do it when there can be multiple users all at the same location trying to request captioning for the same thing?

Subil Abraham – 03/04/2020 – Pull the Plug

March 4, 2020 Subil Abraham 1 Comment

The paper proposes a way of solving the issue of deciding when a computer or human should do the work of foreground segmentation of images. Foreground segmentation is a common task in computer vision where the idea is that there is an element in an image that is the focus of the image and that is what is needed for actual processing. However, automatic foreground segmentation is not always reliable so sometimes it is necessary to get humans to do it. The important question is deciding which images you send to humans for segmentation because hiring humans are expensive. The paper proposes a machine learning method that calculates the quality of a given coarse or fine grained segmentation and decide if it is necessary to bring in a human to do the segmentation. They evaluate their framework by examining the quality of different segmentation algorithms and are able to acheive the quality equivalent to 100% human work by using only 32.5% human effort for Grab Cut segmentation, 65% human effort for Chan Vese, and 70% human effort for Lankton.

The authors have pursued a truly interesting idea in that they are not trying to create a better way of automatic image segmentation, but rather creating a way of determining if the auto image segmentation is good enough. My initial thought was couldn’t something like this be used to just make a better automated image segmenter? I mean, if you can tell the quality, then you know how to make it better. But apparently that’s a hard enough problem that it is far more helpful to just defer to a human when you predict that your segmentation quality is not where you want it. It’s interesting that they talk about pulling the plug on both computers and humans but the focus of the paper seems to be focused on pulling the plug on computers i.e. the human workers are the backup plan in case the computer can’t do the quality work and not the other way around. This applies to both their cases, coarse grained and fine grained segmentation work. I would like to see future work where the primary work is done by humans first and then test to see how pulling the plug on the human work would be effective and where the productivity would increase. This would have to be work in something that is purely in the human domain (i.e. can’t use regular office work because that is easily automatable).

What are examples of work where we pull the plug on the human first, rather pulling the plug on computers?
It’s an interesting turn around that we are using AI effort to determine quality and decide when to bring humans in, rather than improving the AI of the original task itself. What other tasks could you apply this, where there are existing AI methods but an AI way of determining quality and deciding when to bring in humans would be useful?
How would you set up a segmentation workflow (or another application’s workflow) where when you pull the plug on the computer or human, you are giving the best case result to the other for improvement, rather than starting over from scratch?

03/04/2020 – Pull the Plug? Predicting If Computers or Humans Should Segment Image – Yuhang Liu

March 4, 2020 yuhang Liu 1 Comment

Summary:

This paper examines a new image segmentation method. Image segmentation is a key step in any image analysis task. There have been many methods before, including low-efficiency manual methods and automated methods that can produce high-quality pictures, but these methods have certain disadvantages. The authors therefore propose a distribution framework that can predict how best to assign fixed labor to collect higher quality segmentation for a given image and automated method. Specifically, the author has implemented two systems, which can perform the following processing on images when doing image segmentation:

Use computers instead of humans to create the rough segmentation needed to initialize the segmentation tool,
Use computers to replace humans to create the final fine-grained segmentation. The final experiments also proved that relying on this hybrid, interactive segmentation system can achieve faster and more efficient segmentation.

Reflection:

Once, I did a related image recognition project. Our subject is a railway turnout monitoring system based on computer vision, which is to detect the turnout of the railroad track from the picture, and the most critical step is to separate the outline of the railroad track. At that time, we only using the method of computer separation, the main problem we encountered at the time was that when the scene became complicated, we would face to complex line segments, which would affect the detection results. As mentioned in this paper, using human-machine, the combined method can greatly improve the accuracy rate. I very much agree with it, and hope that one day I can try it myself. At the same time, what I most agree with is that the system can automatically assign work instead of all photos going through a same process. For a photo, only the machine can participate, or artificial processing is required. This variety of interactive methods, It is far more advantageous than a single method, which can greatly save workers’ time without affecting accuracy, and the most important point is that complex interaction methods can adapt to process more diverse pictures. Finally, I think similar operations can be applied to other aspects. This method of assigning tasks through the system can coordinate the working relationship between humans and machines, for example, in other fields, such as sound sentiment analysis and musical background separation. In these aspects, humans have the incomparable advantages of machines and can achieve good results, but it takes a long time and is very expensive. Therefore, if we can classify this kind of thinking, deal with the common working relationship between humans and machines, and give complex situations to people or pass the rough points of the machine first, then the separation cost will be greatly reduced, and the accuracy rate will not be affected, so I It is believed that this method has great application prospects, not only because of the many application directions of image separation, but we can also learn from this idea to complete more detailed analysis in more fields.

Question:

Is this idea of cooperation between man and machine worth learning?
Because the system defines the working range of people and machines, will the machine reduce the accuracy due to the results of human work?
Does man-machine cooperation pose new problems, such as increasing costs?

03/04/20 – Akshita Jha – Toward Scalable Social Alt Text: Conversational Crowdsourcing as a Tool for Refining Vision-to-Language Technology for the Blind

March 4, 2020 Akshita Jha 1 Comment

Summary:
“Toward Scalable Social Alt Text: Conversational Crowdsourcing as a Tool for Refining Vision-to-Language Technology for the Blind” by Salisbury et. al. talks about the important problem of accessibility. The authors talk about the challenges that arise from an automatic image captioning system and how the imperfections in the system may hinder a blind person’s understanding of social media posts that have embedded imagery. The authors use mixed methods to evaluate and subsequently modify the captions generated by the automated system for images embedded in social media posts. They study how crowdsourcing can enhance the existing workflows and that provide scalable and useful alt text for the blind. The imperfections of the current automated captioning system hinder the user’s understanding of an image. The authors do a detailed analysis of the conversations collected by them to design user-friendly experiences that can effectively assist blind users. The authors focus on three research questions: (i) What value is provided by a state-of-the-art vision-to-language API in assisting BVI users, and what are the areas for improvement? (ii) What are the trade-offs between alternative workflows
for the crowd assisting BVI users? (iii) Can human-in-the loop workflows result in reusable content that can be shared with other BVI users? The authors study varying levels of human engagements and automated systems to come up with a final system that better understands the requirements for creating good quality al-text for blind and visually impaired users.

Reflections:
This is an interesting work as it talks about the often ignored problem of accessibility. The authors focus on images embedded in social media posts. Most of the times the automatic captions given by an automated system trained using a machine learning algorithm are inadequate and non descriptive. This might not be so much of a problem for day to day users but can be a huge challenge for blind people. This is a thoughtful analysis done by the authors keeping accessibility in mind. The authors validate their approach by running a follow-up study with seven blind and visually impaired users. The users were asked to compare the uncorrected vision to language caption and the alt text provided by their system. The findings showed that the blind and visually impaired users would prefer the conversational system designed by the authors to better understand the images. However, if the authors had taken the feedback from the target user group while developing the system that would have been more helpful instead of just asking the users to test the system. Also, the tweets used by the authors might not be representative of the kinds of tweets in the target users’ timeline.

Questions:
1. What do you think about the approach taken by the authors to generate the alt-text?
2. Would it have been helpful to conduct a survey to understand the needs of the blind and visually impaired users before developing the system?
3. Don’t you think using a conversational agent to understand the image embedded in tweets is too cumbersome and time consuming?

03/04/2020 – Toward Scalable Social Alt Text: Conversational Crowdsourcing as a Tool for Reﬁning Vision-to-Language Technology for the Blind – Yuhang Liu

March 4, 2020 yuhang Liu 1 Comment

Summary:

The authors of this paper explored that visually impaired users are limited by the availability of suitable alternative text when accessing images in social media. The author believes that the beneficial of those new tools that can automatically generate captions are unknown to the blind. So through experiments, the authors studied how to use crowdsourcing to evaluate the value provided by existing automation methods, and how to provide a scalable and useful alternative text workflow for blind users. Using real-time crowdsourcing, the authors designed crowd-interaction experiments that can change the depth. These experiments can help explain the shortcomings of existing methods. The experiments show that the shortcomings of existing AI image captioning systems often prevent users from understanding the images they cannot see , And even some conversations can produce erroneous results, which greatly affect the user experience. The authors carried out a detailed analysis and designed a design that is scalable, requires crowdsourced workers to participate in improving the display content, and can effectively help users without real-time interaction.

Reflection:

First of all, I very much agree with the author’s approach. In a society where the role of social networks is increasingly important, we really should strive to make social media serve more people, especially for the disadvantaged groups in our lives. The blind daliy travel inconveniently, social media is their main way to understand the world, so designing such a system would be a very good idea if it can help them. Secondly, the author used the crowdsourcing method to study the existing methods. The method they designed is also very effective. As a cheap human resource, the crowdsourcing method can test a large number of systems in a short time, but I think this method There are also some limitations. It may be difficult for these crowdsourced workers to think about the problem from the perspective of the blind, which makes their ideas, although similar to the blind, not very accurate, so there are some gaps of the results with blind users. Finally, I have some doubts about the system proposed by the author. The authors finally proposed a workflow that combines different levels of automation and human participation. This shows that this interaction requires the participation of another person, so I think this interaction There are some disadvantages to this method. Not only will it cause a certain delay, but because it requires other human resources, it also requires some blind users to pay more. I think the ultimate direction of development should be free from human constraints, so I think we can compare the results of workers with the original results and let machine learning. That is to use the results of crowdsourcing workers for machine learning. I think it can reduce the cost of the system while increasing the efficiency of the system, and provide faster and better services for more blind users.

Question：

Do you think there is a better way to implement these functions, such as studying the answers of workers, and achieving a completely automatic display system?
Are there some disadvantages to using crowdsourcing platforms?
Is it better to change text to speech for the visually impaired?