Archive for the ‘iTechnology’ Category

Google Hangouts to Facilitate Classroom Discussion

Today, a lot of student work is done on computer. To facilitate discussion and encourage students to share and demonstrate their work easily in class room, Google Hangouts can be a good tool.

For classroom use, here is the basic configuration:

  • A projector is connected to the teacher’s laptop, and projecting to the screen that everyone can see.
  • The teacher log in his or her google account, and generate a Google Hangouts link (go to, and click “Video Call”. It will open a new page, you can copy the url of the page. )
  • Then you can put the link in a publicly shared calendar items for the scheduled courses. E.g. you can put the link in the description of the related calendar item.
  • The teacher’s laptop and the students’ laptops should be able to have internet access so they can see the Google calendar items and connect to linked google hangouts.

Here is how to use it:

  • Both the teacher and  the students who are going to present their work go to the calendar item and click the provided hangouts link.
  • The teacher shows the webpage with the hangouts to the projected screen. And everyone can see the people logged in.
  • The person who wants to demonstrate their work share the screen (click the menu icon on the top right, and select “Share screen”), then student can go to the work he or she wants to demonstrate.
  •  The teacher can click the icon of the student who wants to present in the Google Hangouts page, then it will switch to the content the student demonstrate.

Pros and Cons:

  • It will minimize the equipment / presentation set up time, and make the demonstration and dissection in a group easily. It will help students focusing on the discussion part.
    • For the students, they just click the hangouts link, join the hangouts and share the screen.
    • For the teacher, he / she just click the hangouts link, join the hangouts and switch to the different students who want to share.
  • Depends on the internet speed, there is some lag on screen sharing.  Anyway, if the student are not going to show a video, it will still be fine.

So far, my students are enjoying this hangouts experience.

And definitely, it will be good for online class discussion as well.


Categories: iTechnology

Rescue Corrupted Disk / SD Card, etc.

About a year ago, my macbook pro died with a corrupted hard disk. I tried multiple ways, the disk just could not be fixed and was not readable or bootable. I had to replace it with a new hard disk, and I was still considering the possibility to get the files back. I tried an open source recovery tool, and it really helped. The basic method was:
1. Make a bootable USB drive;
2. Reboot the system from the USB drive;
3. Run the tool and recover the corrupted files from the dead disk to another selected place.
This tool worked on the command line, but I could not exactly remember the name so far.

Now, one of my SD Card corrupted. To rescue the lost pictures and videos, I searched online and found a tool named TestDisk & PhotoRec, command line based open source software. It works great. It just brings back my memory about the corrupted hard disk for the macbook pro. I am not sure if they are the same one, but they do work the similar way.

Keep a record here for future reference:

Apply Regular Expression Search in Word

Find and replace text by using regular expressions (Advanced)

Simply find Find and Replace” and select “wildcards”, and then you can apply the regular expressions. And the very basic rules are:

To find Type Example
Any single character ? s?t finds sat and set.
Any string of characters * s*d finds sad and started.
The beginning of a word < <(inter) finds interesting and intercept, but not splintered.
The end of a word > (in)> finds in and within, but not interesting.
One of the specified characters [ ] w[io]n finds win and won.
Any single character in this range [-] [r-t]ight finds right and sight. Ranges must be in ascending order.
Any single character except the characters in the range inside the brackets [!x-z] t[!a-m]ck finds tock and tuck, but not tack or tick.
Exactly n occurrences of the previous character or expression {n} fe{2}d finds feed but not fed.
At least n occurrences of the previous character or expression {n,} fe{1,}d finds fed and feed.
From n to m occurrences of the previous character or expression {n,m} 10{1,3} finds 10, 100, and 1000.
One or more occurrences of the previous character or expression @ lo@t finds lot and loot.

For representing the special symbols above, you can use “\” in front of the symbol to identify it. For example, if we want symbol “*”, we should use “\*” in the regular expression.

Validate Email Address in Google Form

Google Form provides a good function to check the respondents’ answer in accordance with customized guidelines. Here is how to set a regular expression to make sure the respondent fill in a valid email address:

  1. Create a form.
  2. From the Insert menu, select “Text” from the list.
  3. Click Advanced Settings at the bottom of the question.
  4. Select Data validation to show the data validation options.
  5. Select Regular expression, Matches.
  6. Copy “^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$” to the “Patten” field.
  7. Copy “Invalid email address.” to the “Custom error text” field.
  8. Done.

Now, respondents who enter invalid email address will see an error message “Invalid email address.”


  1. Validate answers in your form.
  2. Apps Script Tutorial: Validation.
Categories: iTechnology

Share: “1 Million Users: What I Learned”

01/29/2013 1 comment

I have tried Jotform for my class. Very neat product. Especially, I enjoyed the function to sync the submitted files to dropbox. This semester I notice some nice improvement of it, and I love the function to link to google spreadsheet. So, it brings a lot of potentials.

Today, the founder Aytekin Tank shared a post: “1 Million Users: What I Learned”. Nice article and congratulations to their team!

Categories: iTechnology

Google Search Tips

Categories: iTechnology

To Students: Simplify / Manage Your Life with Google Calendar

10/18/2012 2 comments

From time to time, some of the students can not show up in classes, miss homework deadlines, scheduled appointments, and even exams. Recently, I found most of the students didn’t use any tool to manage their schedules. They try to keep everything in their mind, and if they forget anything, then they miss it.

I have tried to send out reminders regularly. However, I realize that students should know how to manage their own schedule. Here is a technical tip to help – simply use google calendar and task to put everything in one place.

Here are some tutorial resources:

1. Blog post: simplify/manage your life with google calendar

2. Youtube: Google Calendar and Tasks Tutorial

Categories: iTechnology