Open Educational Resources - Science topic

Dear Abdelmoheiman Zakaria

Thank you very much for your help.

Well it depends on the potential that we applied. Positive potential gives oxidation reaction and negative potential gives reduction potential. If working electrode is in oxidation state then counter/ auxiliary electrode get reduced. It also depends on chemical behaviour of the electrolyte and assays that you studied.

Hi Arunkumar Gunasekaran,

Herein, I am providing my experimental procedure to check the potential of the Hg/HgO (1 M KOH) reference electrode by using an SCE (saturated KCl). Please give it a try for your Hg/HgO (1 M NaOH).

Water oxidation is 4-electron process. The potential of water oxidation is the average potential of 4-steps (the sum of four potentials for each step divided by 4). The first step is water oxidation to HO-radical, which has a very high potential. Thus, you need to build a multi-electron catalytic route to avoid the hydroxyl radical formation

Dear Prof. Couto!

You raised an important topic. I think the attitude and mindset of Global North to help Global South is critical in ensuring quality considerations and responding to emerging sudden problems. I think it is vital that people in developing countries could utilize knowledge the same way as people in developed countries. This is a key aspect when mitigating the risks of COVID-19 pandemic:

1) Zhang, X., Tlili, A., Shubeck, K. et al. Teachers’ adoption of an open and interactive e-book for teaching K-12 students Artificial Intelligence: a mixed methods inquiry. Smart Learn. Environ. 8, 34 (2021). https://doi.org/10.1186/s40561-021-00176-5 Open access:

2) Huang, R., Tlili, A., Chang, TW. et al. Disrupted classes, undisrupted learning during COVID-19 outbreak in China: application of open educational practices and resources. Smart Learn. Environ. 7, 19 (2020). https://doi.org/10.1186/s40561-020-00125-8 Open access:

Yours sincerely, Bulcsu Szekely

Dear Rajkiran Shivade,

you should choose a catalytic ink preparation protocol to meet your standars (some techniques use ethanol or methanol or water and amount of alcochol, others use different amounts of nafion, etc. you should choose wise and always have in mind the metals/materials that compose your catalyst- their solubility, etc.).

Then, you should mix everythink well in ultrasonicator or magnetic stirrer (the instrument used, depends on the preparation protocol) and then you should deposite the appropriate amount of ink onto the rotating disk electrode (later you can use this amount to theoritically calculate the metal loading onto the electrode).

Then, the drying process will follow1) in room temperature, 2) or under thermal raridation, 3) or by using the rotating disk electrode with very small velocity (that ensures uniform drying of the paste onto the electrode surface).

***you can search for papers concerning ORR and OER experiments in three-electrode system, in the experimental procedure chapter the catalytic ink preparation should be mentioned.

Sina Safavi You are correct that " the oxidation state of the transition metal and transition metal species forms in solution are depend on PH and concentration of the metal salt solution." " Are you leading me to this concept?" Yes

When you are looking at overpotential of OER, you have to keep in mind the second half reaction, HER. The potential required for water splitting is pH independent, 1.24 V. In alkaline medium you have lower overpotential for OER but higher for HER

Dear Samaher, your research would need to start from the research question(s) that you want to answer - and not from the research instruments you are using. The instrument itself is only a way to gather data that can help you to answer your question(s). So the simplest idea to help you would be to turn your research back on its feet: Start with want you want to find out about (which usually derives from what is already know/not yet known in your area of research) - and only then pick the scales that are appropriate to measure the student characteristics that you are interested in.

@Sourav Roy Thanks for your kindly reply!

Hello Lithin,

thanks for posting this interesting technical question on RG. A good description of the method for cleaning nickel electrodes for electrochemical measurements is provided in the rather old article which is attached as pdf file. It is outlined here that (citation): "Prior to each measurement, the electrode was mechanically polished to a mirror-like finish. The oxide film on the electrode surface, arising from the polishing process, was removed with dilute HCl solution. The electrode was then rinsed thoroughly with distilled water."

I hope this helps. Good luck with your work and best wishes!

Yes, please make sure your Y-axis in that plot is overpotential instead of potential.

Sincerely,

Microporous with dimensions less than 2 nm are suitable for adsorption applications, but for electrocatalysis, mesoporous is more suitable to facilitate ion transfer. In general, among all these structures, a hierarchical structure with a variety of porosity dimensions is the best choice for your purpose. Of course, to choose the right type of structure, the ratio of mesopores to macro and microporosity must be at least double. Increasing the pyrolysis temperature in the furnace up to 900 ° C helps to achieve the mesoporosity structure. In addition, the use of steam-assisted physical activation helps to form more mesopores.

Dear Nouman,

many thanks for sharing this very interesting technical question with the RG community. First of all I fully agree with the statement by Yurii V Geletii. We are synthetic chemists, so I'm not a proven expert in catalysis. However, to my knowledge the behavior of heterogeneous catalysts in certain reactions is still largely based on trial and error. For a very instructive overview of the various catalysts used in OER and HER reactions please have a look at the following useful review article:

The paper has been pubblished Open Access and is freely available on the internet (please see attachment).

In this context it is interesting to note that last year researchers reported the surprising finding that certain bifunctional catalysts can catalyze both the HER and OER reactions. For more information about this finding please see the following very interesting article:

Unfortunately this paper has not yet been posted as public full text on RG. However, three of the authors have RG profiles. Thus chances are that you can request the full text e.g. from the corresponding author via RG.

Good luck with your work and best wishes, Frank Edelmann

Utilizing those catalysts in practical device for commercialization of H2 and/or O2 gas along with making a couple with water electrolyzer and H2 fuel cell device would be the next step. Good reaction rate, pure products formation, low energy consumption and electrode stability should be checked in practical device.

I have already answered your question in another thread. To avoid confusions, plz write what is OER.

In general, the electrocatalytic activity can be quantified based on the current density (at a specific voltage）per mass (A/g).

Dear Nabeel,

In industry, stability is usually much more important than activity, which is the direct opposite of most academic papers. The vast majority of catalysts reported in academia either have no proper stability assessment at all, or limit themselves to 2-24 hours of stability at 10 mA/cm2, which holds extremely little value.

Additionally, many of the purpoted 'facile' catalyst syntheses in papers are too complex (several lengthy steps), require exceedingly expensive start materials, or are simply unsuitable - the result is a powder, which is not easily applied to a support.

The gap between academia and industry is larger than ever nowadays. There are some exceptions though: an example of a good paper which, in my opinion, seems well-rooted in industry, can be found here: doi.org/10.3390/ma12081336.

Best regards,

Jan

Dear Ming-Jun, many thanks for asking this very interesting technical question. Of course it is very difficult to judge as an outsider what possibly went wrong in your case. My personal suggestion would be to discuss this problem in detailwith your PhD supervisor. Moreover, you can try to reproduce a procedure described in the literature and see if you get the same results. Unfortunately, research articles in this field do not report negative results and do not explain what could perhaps go wrong. When you have a look at relevant articles on this topic you only read about "Efficient.." or "Highly efficient...". For example, please have a closer look at the following potentially useful articles:

High efficiency nitrogen doping and single atom cobalt anchoring via supermolecules for oxygen reduction electrocatalysis

Co, N co-doped porous carbons as high-performance oxygen reduction electrocatalysts

Single-Atom Catalysts for Electrochemical Hydrogen Evolution Reaction: Recent Advances and Future Perspectives

The latter article is freely available as public full text on RG.

Good luck with your work!

Dear Amravati Singh,

The pyrolysis temperature may have so many unknown effect on the performance of the catalysts, such as crystallization, coordination environment and may the components of your material. So you must consider different reasons when you design your project.

Best wishes !

Yes, Prof. Vadim S. Gorshkov

Visualization is a very extensive subject, not easy to cover or to define some limits on it. I am learning all this & I find it interesting, for example in Moodle, scientists develop a particular plugin for visualization in teaching and learning asynchronously, and that is a Ph.D. thesis that well deserves attention.

Best Regards.

Hi Szymon,

From what I have seen for alkaline media:

Nickel is chemically resistant, and a good OER catalyst. Can dislodge catalyst during charging.

Titanium doesn't evolve oxygen during charging, but you may get some dissolution initially.

Steel may release ions such as Fe, Cr, Mn over time that can contaminate the zinc electrode.

Prof. Stefanie Lietze,

H5P has recently integrated a plugin using HTML5 APIs in Moodle.

" the contribution of pH to energy change for each reaction step is given by (pHk_bTln10) " is not correct. The catalytic OER and ORR are multistep processes. Each 1e transfer reaction has its own pH dependence.

With use of reference and counter electrode in voltmeter you can find the cathodic and anodic potentials

" Usually for OER, for example, a potential range between -0.1 to 1 is chosen. " Who chooses this range?

" Why take a CV in an area where the reaction does not begin? " This is the answer for your question!

Yurii V Geletii Thanks for your suggestion.

Dear Mr. Cornel Radu

Thank you for your help. Unfortunately, it did not switch again. It starts at 0.7 V and continues at this potential until it reaches the potential limit and then stops (for the trial I chose 5 as the number of segments). I do not know what the problem can be.

Thanks for Yusi's help@Yusi Xe. I have got the shinning polished surface of Ni foil. In phospherou acid, the OER in anode can happen at lower voltage, which would disturb the polish process. 70% H2SO4 would be better electrolyte for Ni polish. The core point for this process is to maintain as close and parallel as possible between anode and your cathode. The voltage can be chosen from 3.6-6V.

Since Scopus to ORCID is possible and ORCID to Scopus is not possible, the only way to do that is by using manual addition for those that are not seen automatically.

Dear Prof. Rey Segundo Guerrero-Proenza ,

I do believe that Microsoft Team is actively engaged as a current trend worldwide because it is an online collaboration workspace that brings together instant messaging, threaded conversations, meetings, audio or video calls, desktop and file sharing.

In addition, it works with all Office 365 apps like Word, Excel, PowerPoint, OneDrive, SharePoint, OneNote, and probably with 365 Dynamics and Azure as well.

Some features are free for educators. The speed of the computer can be a problem although.

Hi,

The Rct will be affected by the overpotential you apply, i.e. the higher the overpotential the lower the size of the semicircle in the Nyquist plot. Given that one of the main requirements for EIS is a stable system with a linear response between E and I, I would avoid the region where mass transport limitation kicks in (in you are working with RDE just collect some CVs at different rotation rates and avoid all potentials higher than the value where the CVs split). This would ease your fitting and you avoid bubble formation. Alternatively, you could use the Tafel plot to check what is the potential range with linear response of IvsE. Another reason to avoid high E is that your catalyst may peel off the surface or corrode, which means that your system is no longer stable. I used to work with Ir catalysts and an overpotential of around 270mV was a good value for me. If you're working with RDE, be careful with long term stability tests: microbubbles can get trapped in the catalyst layer leading to a false degradation effect. What is changing is just the surface area. What I think is crucial to benchmark the catalysts and make them comparable is however the normalization of their activity (current) by the available active sites. I do not know your system, but using some stripping methods (CO stripping as well as metal stripping) could be a viable option. Also the determination of the capacity by EIS could be an option, unless you're using nanoparticles supported on an inert conducting substrate. I see that knowing the Rct is important, but how can you determine a reliable value without knowing the actual surface area of your catalyst? By simply doubling your surface area you would be capable to deliver more current, but this does not make your catalyst more active, since you could simply obtain the same result by using more catalyst.

Hope that was helpful.

Dear Prof. Nazime Tuncay

Interesting yes, Khan Academy-KA is a virtual learning environment-VLE, but it is not a open source software platform as it is Moodle for example, I am just guessing.

Let me elaborate on this: KA has thousands of files with instructional content classify in: videos, exercises and articles.

For each skill to be learned in KA, these 3 resources will go along with each student. As say KA developers, it has expert-created content & resources for every course and level. Always free. But teachers cannot change those resources content, only use it, therefore I guess that KA is not an open source software.

Regarding to the class issue, in order to create a virtual class in KA, the teachers home feed creates the class with the student names, the parent names and it gives each student a free email account. Also a google classroom can be imported inside KA according to them. That option I haven´t try. KA is really worth to explore.

Dear Suncheol Kim,

could you note, please, what is the V_DC polarization^[1] values(s), of the related EIS measurements^[2,3] , that you have shown (Nyquist-plot)^[4], here ?

i guess OER but the graph sign should change...you may check setting of your electrochemical station...

I think Availability of the internet is vital for discussion first, purpose in terms of what activity like assessment, debate, etc., should be directed at, lecturer's level of awareness, Students' readiness, leadership support, as well as whether there is government policy to mandate such plans.

You can conduct a survey to understand the pulse of the target audience. The survey questions can originate from some top-level areas like; Concept Usefulness, Ease of understanding, Ease of implementation and Value addition by the framework. You can have multiple questions under each broad category. Please keep some space for open ended answers also. Analyse the responses and conclude. You can have a look into the similar research at;

There is no a strict definition of the "onset potential.

This discussion might be helpful

Hi

How to calculate onset potential of OER? Which method you have used to calculate it?

Dear Chinnasamy,

I'm going to guess that those reported articles concern OER catalysts based on 3d transition metals (Co, Ni/Fe, Mn) or other non-noble materials such as functionalized carbon. These catalysts are generally only stable and OER active in basic solutions. The 1 M concentration is probably to increase conductivity of the working solution, to minimize ohmic drop-related issues.

It depends on how you do define OERs: do you include also creative-common resources to that category or not?

I have used a lot e.g. openclipart.org (which has very nice linedrawings to illustrate materials/slides and also wikimedia commons, where you can found media files.

But, well, do you mean public domain materials with OER or what?

dear Noorulain Babar; I think it's better to make electrochemical Impedance Spectroscopy (EIS) measurement to evaluate the behavior of the oxidized sample and to calculate the capacitance. you can read https://www.wiley.com/enaf/Impedance+Spectroscopy%3A+Theory%2C+Experiment%2C+and+Applications%2C+2nd+Edition-p-9780471647492.

I am not sure if you are looking for logical statements or actual examples.

If REAL examples, here are three:

(1) Publishing in many pedagogical journals is fast and easy. They often have preset rules about how the writeup should be, etc. and you can write a pedagogical article up in a weekend. When I was a young scholar I wrote one or two every year about class activities, etc. It gets your name seen, can be an easy and free ticket to a conference when you "need a paper" to get funded, and takes nothing away from your more important research.

(2) Look for book chapters on topics you have expertise in. They are almost always less competitive than an article, and once you have a reputation in an area are very easy to get.

(3) Look for special issues in journals, they are almost always substantially less competitive than a regular publication in the same journal.

If you are looking for illustrations of the concept, the Turtle and the Hare parable is one. The "Melanoma has killed more people than war" is another. And, Sun Tzu wrote: “If you wait by the river long enough, the bodies of your enemies will float by.”

Ingrid Del Valle García Carreño thanks for your comment ingrid.

I added a specific example for a workshop I'm working on here. I hope that would make it clearer.

I have taken many online classes in the past and they were mostly conducted through the Blackboard, and a few were also supported by the third party applications, such as Google Docs, Facebook Groups, and MindTap. Somehow it appealed to me more when the Blackboard was supported by the third parties.

Tafel equation is derived assuming that a single reversible redox reaction takes place on electrode. OER is more complex process and I doubt that Tafel equation can be used in this case. In addition, it's very important how you measure the current. Theoretically, ohmic resistance must be very small and diffusion (mass transfer) should not affect the current.

There are plenty of information in the Google that are quite helpful for consulting any delicate issues in the academic arena. It has reduced the chances of starvation for knowledge hungry people in different parts of the world. We are fortunate to a part of these facilities.

Access to reliable, modern devices from which to access content.

Hi Ivan!

A lot of choices here.

You can just declare how people can use it with Creative Commons licensing (which is legally defined in most countries) https://creativecommons.org/about/program-areas/education-oer/ , you can add metadata just to make it easier to find and understand what it is within general systems, such as libraries with Dublin Core http://dublincore.org/specifications/ , or you could also, if motivated by how your LMS works, use IEEE LOM (Learning Object Metadata) https://www.jiscmail.ac.uk/cgi-bin/filearea.cgi?LMGT1=DCC-PEER-REVIEW&a=get&f=/Draft_Instalments/LOM.pdf or SCORM (Shareable Content Reference Model) https://scorm.com/scorm-explained/ which is a "de-facto-standard in the e-learning industry, or IMS metadata https://www.imsglobal.org/metadata/index.html .

You could alterantively just upload it to Merlot (one of the metadata repositories / referatories out there) or similar database of OER and just provide the info the site asks for to make it searchable. https://www.merlot.org/merlot/index.htm

Here is a good example of simplified informaiton about handling created OER https://oercommons.s3.amazonaws.com/media/editor/36531/Creating_OER_cards_USQ_Oct17.pdf

Hope something of this helps. I have earlier been active in creating a lot of OER, then often called "Learning objects" in biohydrometallurgy, But there may be more up to date answers to this quesiton as well.

@ Rey Segundo Guerrero-Proenza

Let ( X, T) is a topological space. T is the topological structure on X.

X is the whole space ( closed and open: clopen)

It is obvious by the axioms: X belongs to T.

A is an open subset of X, that means A belongs to T.

The boundary of the open set A: b(A) is not necessarily empty.

But A does not include any of its boundary points.

.i.e., ( x belongs to b(A) [ non-empty set ], but x doesn't belong A).

( small x is an element, not the whole space X).

Example: In R the Euclidean space with the usual topology on R.

R is closed and open at the same time( clopen set).

For a and b are distinct real numbers, A = ( a, b ) the open interval in R,

A= (a, b) is open in R.

The boundary set of A is b(A)= { a, b } is non empty set,

neither a nor b belongs to A.

Dear BreAnne,

actually, it's highly difficult to predict an interaction between two proteins because, as said Steingrimur, it might be strongly related to the 3D structure.

However, there is case for which it becomes a bit less difficult: when the protein binds to a linear motif. A motif is a short amino acid sequence (of about 3 to 6 residues). In this case, the interaction is mostly driven by the sequence since the motif is unfolded most of the time.

You may find interesting details at the ELM website (http://elm.eu.org/), which stands for Eukaryotic Linear Motif. It's a manually curated database based on literature. You enter a protein sequence and you'll see all the putative motifs bound to it. Then it's also possible to search for a special motif if you already know it.

Best regards

Yves

Hello, and thank you for the suggestions! Neil

Thank you Riina Vuorikari for uploading the Travel well dataset

Awesome - thanks a lot!

As said by Artur Braun,

It is very crucial in the field of water electrolysis. Actually, carbon paper is not a good substrate electrode for OER in either acid or alkaline medium because of corrosion of carbon (corroded to CO2 and CO). Moreover, Pt/C is not also a better candidate for the OER, you can try nickel as anode material for alkaline water electrolysis. Depending on the carbon paper grade, the stability will.....Actually, the brown color denotes the dissolution of carbon I think, because Pt is highly stable in alkali as well as acid. So you just check the properties of carbon in the Pt, take Raman or XPS to confirm the structural properties. Also, take a ICPMS analysis to confirm the carbon leach out....

Hope this will help you

Yeah I know sample peeling is possible but suppose if it is not there actually what measurements I am taking it just finishes in 2 Hr (30 min saturation, CV and LSV) so after that interval I want to replace my sample with different component. 

No peeling off have happened now? 

Please describe your conditions in more details.  You didn't mention the initial salt. If it is KClO4 the reduction process will give KClO3! In KCl the situation is opposite.

The Cl2  reaction with water is strongly dependent on the temperature. You may get CLO- ClO3- and also ClO4- anions in mixture at different ratios

Have you come across OERhub (http://oerhub.net/)? They have some interesting research

In principle there shouldn't be much difference because the germination and attachment of holoparasitic Orobanchaceae are induced by root exudates and not germination-related compounds from the host. It might be argued that planted seedlings can be somewhat "stronger" against the parasite than those exposed to the parasite from the very beginning, but even if this difference is real it would be probably outweighed by the transplant shock. I hope this helps a bit. Regards.

Hi,

Please find attached some articles that will contribute to your literature.

Best Wishes

si por supuesto le recomiendo el sitio de la Universidad TEcnológica de Monterrey México donde utilizan simuladores también las universidades marítimas tienen  simuladores para la enseñanza de tripulaciones en escenarios difíciles.

Hope the following helps:

Battro, A. M. (2013). One Laptop Per Child: Comments on Jeffrey James's Critique. Social Science Computer Review, 31(1), 133-135. doi:10.1177/0894439311421752

Beuermann, D. W., Cristia, J., Cueto, S., Malamud, O., & Cruz-Aguayo, Y. (2015). One Laptop per Child at Home: Short-Term Impacts from a Randomized Experiment in Peru. American Economic Journal: Applied Economics, 7(2), 53-80. doi:http://www.aeaweb.org/aej-applied/

de Oliveira Kist, S., Soares Carvalho, M. J., & de Vargas Bittencourt, J. (2013). One Laptop per Child and its Implications for the Process of Written Language Learning: A Case Study in Brazil. Revista Electrónica de Investigación Educativa, 15(2), 51-68.

Fajebe, A. A., Best, M. L., & Smyth, T. N. (2013). Is the One Laptop Per Child Enough? Viewpoints from Classroom Teachers in Rwanda. Information Technologies & International Development, 9(3), 29-42.

James, J. (2014). Economics of the one laptop per child in India. Current Science (00113891), 106(8), 1061-1063.

James, J. (2015). Macroeconomic Consequences of the One Laptop per Child Project. Journal of International Development(1), 144. doi:10.1002/jid.3023/abstract

Shinobu, Y., Javzan, S., Jun-ichi, T., & Khishigbuyan, D.-O. (2014). The Effect of Using XO Computers on Students' Mathematics and Reading Abilities: Evidences from Learning Achievement Tests Conducted in Primary Education Schools in Mongolia. International Journal of Education & Development using Information & Communication Technology, 10(2), 89.

Stoloff, D. L. (2013). Learning to change the world: the social impact of one laptop per child, 519.

Hello,

maybe some OER search portal will help You ?

There is a more recent report from HarvardX/MITx, summing up the first two years of their open online courses.

We just wrote an article (currently in review), I can send you directly?

Speaking from personal experience, subject directories are good in that they help organise resources by subject. However, without a comprehensive search tool, a subject direcotry stands to be woefully underutilsed. The multidisciplinary nature of some materials is one reason for this - a material you are seeking in one discipline might have been placed under another discipline because it fits there too. The laborious task of wandering from one link to the other is another reason. One is likely to look for an item under the wrong discipline. One funny thing associated with looking for items in the list is that, one's fallible eyes may not even see the item here is looking for, although it is right there. Performing a search by entering your key term or concept, for me is the best method of locating what you want. This is one reason why putting OER together and rendering them searchable is a good approach to making resources available to library clientele. I found that Google Custom search perfectly does the job

Maybe relevant to your question: http://www.nber.org/papers/w19816 and https://www.gov.uk/government/publications/massive-open-online-courses-and-online-distance-learning-review Good luck with your research Martin!! :)

I've actually called the FCT to ask for more information on this topic. I kept being redirected to different persons and departments until they found someone who actually knew what this was about. This will only affect future projects, so there is no way one can ask for support to publish in open access journals of now ongoing research. Also, being FCT, they are quite vague in that document regarding that support, which may or not be granted (what are the criteria?). Bear also in mind that FCT doesn't even have a protocol with any of the major open access publishers (e.g. BMC and PLOS) for reduction of publication fees for Portuguese authors. What they basically are asking is for researchers to place what is published in peer-review journals in open repositories, something that is already encouraged by many Portuguese institutions, including the University of Porto, the largest in the country. 

There is no such optimization strategy in Web resources or for that matter into Education.

Strategy is a Macro Plan, however Optimization depends on 

Followup with Dr. Nageswara Rao Posinasetti, Professor, University of Northern Iowa · Department of Technology, he is on the education web resources research

I agree. We need easier ways to help researchers to share data and publications and to  get credit for their work. Impactstory could be helpful in this respect.

'Impactstory is an open-source, web-based tool that helps researchers explore and share the diverse impacts of all their research products—from traditional ones like journal articles, to emerging products like blog posts, datasets, and software. By helping researchers tell data-driven stories about their impacts, we're helping to build a new scholarly reward system that values and encourages web-native scholarship.'

My dear @Mardene, please read this experience and initiative, it was held in Belgrade, Serbia! It is on promoting adoption of open educational practice.

To make a MOOC accessible to Deaf and hard of hearing students, you would need to to offer picture in picture capability of a pre-recorded interpretation (by a qualified/certified interpreter) of the video content in the sign language of choice. For example, in the US it would be American Sign Language. For hard of hearing or oral students with hearing loss, captioning in English would also be needed. The reason machine type translation and augmentive communication won't work is because sign language is not just a collection of signs. It has a rich grammatical structure that incorporates facial expressions, mouth morphemes, classifiers and spatial use, in addition to actual sign choices. The reason captioning in English is not a solution for ASL users is because English is a second language, only in our educational system is not taught as a second language. You would also want to ensure that any quizzes or assignments have a video sign component for full accessibility.

hard to know, we have been using it for a few years on campus and whilst it means students can actually read my comments, physically it is far harder on the body and eyes even with a mega screen. Hard copies are far more portable which gives more freedom for marking papers on the run so to speak. However with bulk classes that brings its own issues as well.

I agree with you Erik that smaller length assessments are more manageable as too, a combination of multiple choice questions which can be marked automatically with short answer rationales if more details are needed.

My person experience with MOOCs have been that several have used peer marking which has resulted in some interesting feedback and has meant the workload is being spread around. Consistency of quality remains an issues with this method though.