“Any questions?” How to fight the awkward silence at the end of a presentation?

Questions?

If you ever gave or attended a presentation, you are familiar with this situation: the presenter asks whether there are any questions and … nobody asks anything. This is an awkward situation. Why aren’t there any questions? Is it because everything is clear? Not likely. Everything is never clear. Is it because nobody cares? Well, maybe. There are certainly many people that don’t care. It’s a fact of life. Study your audience, work hard to make the presentation relevant and exciting but still, some people won’t care. Deal with it.

However, the bigger reasons for lack of the questions are human laziness and the fear of being stupid. Nobody likes asking a question that someone will perceive as a stupid one. Sometimes, some people don’t mind asking a question but are embarrassed and prefer not being the first one to break the silence.

What can you do? Usually, I prepare one or two questions by myself. In this case, if nobody asks anything, I say something like “Some people, when they see these results ask me whether it is possible to scale this method to larger sets.”. Then, depending on how confident you are, you may provide the answer or ask “What do you think?”.

You can even prepare a slide that answers your question. In the screenshot below, you may see the slide deck of the presentation I gave in Trento. The blue slide at the end of the deck is the final slide, where I thank the audience for the attention and ask whether there are any questions.

My plan was that if nobody asks me anything, I would say “Thank you again. If you want to learn more practical advises about data visualization, watch the recording of my tutorial, where I present this method  <SLIDE TRANSFER, show the mockup of the “book”>. Also, many people ask me about reading suggestions, this is what I suggest you read: <SLIDE TRANSFER, show the reading pointers>

Screen Shot 2018-09-17 at 10.10.21

Luckily for me, there were questions after my talk. Luckily, one of these questions was about practical advice so I had a perfect excuse to show the next, pre-prepared, slide. Watch this moment on YouTube here.

Graphing Highly Skewed Data – Tom Hopper

screenshot of three graphs: two bar plots and one dot plot with a split graph area

My colleague, Chares Earl, pointed me to this interesting 2010 post that explores different ways to visualize categories of drastically different sizes.

The post author, Tom Hopper, experiments with different ways to deal with “Data Giraffes”. Some of his experiments are really interesting (such as splitting the graph area). In one experiment, Tom Hopper draws bar chart on a log scale. Doing so is considered as a bad practice. Bar charts value (Y) axis must include meaningful zero, which log scale can’t have by its definition.

Other than that, a good read Graphing Highly Skewed Data – Tom Hopper

16-days-work-month — The joys of the Hebrew calendar

Tishrei is the seventh month of the Hebrew calendar that starts with Rosh-HaShana — the Hebrew New Year*. It is a 30 days month that usually occurs in September-October. One interesting feature of Tishrei is the fact that it is full of holidays: Rosh-HaShana (New Year), Yom Kippur (Day of Atonement), first and last days of Sukkot (Feast of Tabernacles) **. All these days are rest days in Israel. Every holiday eve is also a de facto rest day in many industries (high tech included). So now we have 8 resting days that add to the usual Friday/Saturday pairs, resulting in very sparse work weeks. But that’s not all: the period between the first and the last Sukkot days are mostly considered as half working days. Also, the children are at home since all the schools and kindergartens are on vacation so we will treat those days as half working days in the following analysis.

I have counted the number of business days during this 31-day period (one day before the New Year plus the entire month of Tishrei) between 2008 and 2023 CE, and this is what we get:

Dynamics of the number of working days in Tishrei over the years. The average fluctuation is around 16 days

Overall, this period consists of between 15 to 17 non-working days in a single month (31 days, mind you). This is how the working/not-working time during this month looks like this:

tishrei_2018_calendar

Now, having some vacation is nice, but this month is absolutely crazy. There is not a single full working week during this month. It is very similar to the constantly interrupt work day, but at a different scale.

So, next time you wonder why your Israeli colleague, customer or partner barely works during September-October, recall this post.

(*) New Year starts in the seventh’s month? I know this is confusing. That’s because we number Nissan — the month of the Exodus from Egypt as the first month.
(**)If you are an observing Jew, you should add to this list Fast of Gedalia, but we will omit it from this discussion

Sometimes, less is better than more

Illustration: cutting instruments: knife and scissors

Today, during the EuroSciPy conference, I gave a presentation titled “Three most common mistakes in data visualization and how to avoid them”. The title of this presentation is identical to the title of the presentation that I gave in Barcelona earlier this year. The original presentation was approximately one and a half hours long. I knew that EuroSciPy presentations were expected to be shorter, so I was prepared to shorten my talk to half an hour. At some point, a couple of days before departing to Trento, I realized that I was only allocated 15 minutes. Fifteen minutes! Instead of ninety.

Frankly speaking, I was in a panic. I even considered contacting EuroSciPy organizers and asking them to remove my talk from the program. But I was too embarrassed, so I decided to take the risk and started throwing slides away. Overall, I think that I spent eight to ten working hours shortening my presentation. Today, I finally presented it. Based on the result, and on the feedback that I got from the conference audience, I now know that the 15-minutes version is better than the original, longer one. Video recording of my talk is available on Youtube and is embedded below. Below is my slide deck

 

 

Illustration image credit: Photo by Jo Szczepanska on Unsplash

An even better data visualization workshop

Boris Gorelik teaching in front of an audience.

Yesterday, I gave a data visualization workshop at EuroSciPy 2018 in Trento. I spent HOURs building and improving it. I even developed a “simple to use, easy to follow, never failing formula” for data visualization process (I’ll write about it later).

I enjoyed this workshop so much. Both preparing it, and (even more so) delivering it. There were so many useful questions and remarks. The most important remark was made by Gael Varoquaux who pointed out that one of my examples was suboptimal for vision impaired people. The embarrassing part is that one of the last lectures that I gave in my college data visualization course was about visual communication for the visually impaired. That is why the first thing I did when I came to my hotel after the workshop was to fix the error. You may find all the (corrected) material I used in this workshop on GitHub. Below, is the video of the workshop, in case you want to follow it.

 

 

 

Photo credit: picture of me delivering the workshop is by Margriet Groenendijk