I teach programming in Python for elementary data processing, such as load CSV files into memory, calculate statistical values from it, and visualize the result as charts. For each lecture, if it is not online, I spend the first 45 minutes explaining and the last 45 minutes for practices. (As I said, I'm teaching in Japan.) Along with this line, I had already prepared the following materials:

1. Lecture notes containing detailed explanations about Python programming,

2. Slideshows explaining the content of lecture notes briefly, and

3. Homework.

The students watch and listen to my explanation based on the slideshows on each lecture, and then they try to solve problems in Python programming. During the lecture, I walk around the classroom to watch their practices and help them solve the problems. After the lecture, they can learn the omitted detail by referring to the lecture notes at home. The homework verifies their understandings. It worked well in offline teaching.

How can I transform this framework online? It seemed infeasible to watch tens of students writing their programs online in real-time. There was another problem that the university recommended preparing lecture videos. The course is composed of 15 lectures, including two exams. It is easy to say difficult to do the recording of more than ten lecture videos, each of which has about an hour of length. Furthermore, and most importantly, how can I ensure the learning quality of my students? None of these issues are trivial.

What is clear was that I could not afford so much time and money to prepare the online course. I know that there are many online services for education. But, almost all of them are not free. The tool I want should support the hosting of lecture notes, slideshows, homework, and videos. In addition, it is desirable to have editing functionality of those materials online. Of course, it is better to be free.

The nearest answer is Google Workspace and its siblings. It is composed of various applications also convenient for educational purposes. The following list shows what can we use for free:

• Google Site: It is convenient for setting up the lecture portal on which course materials are listed and easily accessible.

• Google Meet: The online meeting service like Zoom. I think the video quality is better than Zoom. One caveat is that the length per meeting is limited to one hour. It is no problem to prepare and use several sessions for a longer lecture.

• Google Calendar: You can embed the calendar into the Google Site. In conjunction with Google Meet, it helps to share the lecture schedules.

• Google Docs: You can use it to write printer-friendly lecture notes. Though it is possible to write them as pages of Google Site, they are not printer-friendly.

• Google Sheets: It is not the best but a practical tool to manage students and scores list.

• Google Slides: It has enough functionality to make slideshows.

• Google Colaboratory: It serves as an online Integrated Development Environment for students. It is also useful as a lecture notes editor since it supports Markdown text writing and TeX equation embedding as part of it.

Every tool mentioned above is free. We can use it without charge.

The volume required to embody a course is substantial. We need careful planning to prepare those materials. My best practice is as follows:

1. Define the learning goal. First of all, we need to define the goal of learning clearly as possible.

2. Break down the goal into sub-goals corresponding to each lecture.

3. Choose the points to set milestone assignments. With these three steps, we have the goal, sub-goals, and checkpoints. These elements comprise the bone structure of your course. Be careful that it is vital to find a balanced structure. Too many assignments make students stressed. Also, it would help if you equalized the volume of each sub-goals.

4. Prepare lecture notes based on the structure defined above. I recommend you make one lecture note for one lecture.

5. Prepare homework. If you have enough time, I also recommend you make exam questions at this point.

6. Make slideshows, each of which is a summary of one lecture note.

7. Generate lecture videos from slideshows and upload them to YouTube. (OPTIONAL) On YouTube, students can watch the videos at any time they want. The YouTube console shows the audience statistics, too.

8. Set up a Google Site as the course portal. We can put the links to lecture notes written by Google Docs/Colaboratory and embed the slideshows, YouTube videos, and the calendar on that site.

9. Publish your site, lecture notes, slideshows, and so on. We can control the access scope of those materials. For example, we can restrict only the authorized students can see the materials. The simple way is to publish them as "Anyone with the link."

As you see, lecture notes are the mother of all other materials. And the goal and sub-goals define the scope of each lecture note.

The simple answer is to use Lecture Video Maker, as you expect. But, it is not free, and I do not necessarily recommend doing so. There are other tools for that purpose. Several of them are:

• Creator Studio ($3.25/month)

• Slides Video Maker (Free)

• Multiple Images to Video (Free)

• Slides To Video (Free?)

• OBS Studio (Free) (has a desktop capturing capability.)

• Microsoft Powerpoint

Please don't ask me about the detail of these tools. However, except for Microsoft Powerpoint, these tools lack essential features like voice recording for each slide.

I think Microsoft Powerpoint is the most powerful choice for ordinary use cases. With Powerpoint, we can record our voice for each slide, apply animations to shapes, embed some captured movies, and overlay BGM and sounds. I believe most of you have already installed it on your computer. So, there is no additional cost to use it in many cases. Or, OBS Studio is another good choice. Though it works just as a desktop capturing tool for the purpose, it is easy to use.

At the very beginning, I used Powerpoint to prepare my lecture videos last year. But I found the following issues:

• It is difficult to estimate the total duration of a generated video. I had to keep it within the timeframe of 45 minutes.

• It has no speech synthesis functionality. I wanted to generate the voice since I edited and updated many parts of my slideshows repeatedly. Without that synthesis, I had to record my voice again and again.

• It is very slow to generate a video. It often requires time longer than the generated video.

That's the reason why I developed Lecture Video Maker. It has convenient features for lecture video generation from Google Slides, supports speech synthesis, and works faster than Powerpoint.

The appropriateness of a tool depends on the use case. Lecture Video Maker is a tool suited for people suffering from issues similar to mine.

At last, I should answer this question. My answer is "not so much." My students didn't spend so much time on my lecture videos. Most of them seemed to skim just a portion of each video. I confirmed that fact through the statistics shown on YouTube Studio.

So, should we avoid spending our precious time on burdensome video making? I don't think so because there are a few students who benefited from those videos. It is another fact I confirmed through my experience. As long as some students would be helped, I cannot ignore its value.

I won't deny the possibility that the quality of my lecture videos was too miserable to attract my students. Better videos might have attracted students and have provided satisfactory experiences. However, it is not easy and not a matter of minutes to prepare such high-quality videos in a sense that it is fun to watch, intelligible, and rich in content.

Course materials are just tools. They could help teachers and students to share knowledge. But it is not sufficient to read and think about those materials. I believe that discussion, homework, Q&A sessions, and so on as a whole embody students' learning. It is no different from offline learning.

In conlusion, a balanced answer is preparing your lecture videos but not spending too much time on them. And I hope my tool and others could help your teaching.