New York Times special front page

Today’s front page of The New York Times contains no images, headlines or articles. It’s a long list of 1.000 names who lost their lives due to corona. A powerful way to honor all these people.

As the death toll from Covid-19 in the United States approaches 100,000, a number expected to be reached in the coming days, editors at The Times have been planning how to mark the grim milestone.

Putting 100,000 dots or stick figures on a page “doesn’t really tell you very much about who these people were, the lives that they lived, what it means for us as a country,” Ms. Landon said. So, she came up with the idea of compiling obituaries and death notices of Covid-19 victims from newspapers large and small across the country, and culling vivid passages from them.

Read more: The Project Behind a Front Page Full of Names


What I’ve been reading this week, 22 December 2019

This is an overview of articles that I read this week and shared via my weekly newsletter. It covers the best of analytics and experimentation related content.

1. One Nation, tracked
Massive investigation into the smartphone tracking industry by The New York Times. Read the article.

2. Biased Algorithms Are Easier to Fix Than Biased People
Racial discrimination by algorithms or by people is harmful — but that’s where the similarities end. Also from NYT. Read the article.

3. Refuted Causal Claims from Observational Studies
Ronny Kohavi shared a new chapter from his upcoming book (available for pre-order). “We review famous examples where causality was claimed as likely in observational studies, but later refuted in studies higher in the hierarchy of evidence, such as randomized controlled experiments.” Read the article.

4. How Imperfect Foods built a culture of experimentation
Read the article.

5. Extending monitoring from application performance to features
Lizzie Eardley from Split explains the advantages of feature monitoring. Read the article.

6. The 3 A’s of becoming a data-driven organization
Accurate, Accessible and Actionable. Read the article.

7. Build a Career in Data Science (book)
Emily Robinson and Jacqueline Nolis have released their new book.
Read more.


What I’ve been reading this week, 8 December 2019

This is an overview of articles that I read this week and shared via my weekly newsletter. It covers the best of analytics and experimentation related content.

1. Recap Conversion Hotel conference 2019
Two weeks ago I visited the ‘Conference Formerly Known as Conversion Hotel’, now known as #CH2019. This was already my fourth visit to what I believe is the best conference in The Netherlands for people into data, analytics and experimentation. Read/watch links to all video summaries, slides, notes, questions and pictures (and get on the notification list for next year).

Earlier this year Simo Ahava already wrote a good blogpost on Intelligent Tracking Prevention (ITP). He recently released “a knowledge sharing resource for the various tracking protection mechanisms implemented by the major browsers and browser engines”. Mandatory reading material for everyone collecting and/or analysing online data. Go to

3. Creating the Experimentation Organization
A short interview with Stefan Thomke about experimentation and his forthcoming book, ‘Experimentation Works‘. “Companies better get on this [experimentation] if they don’t want to be at a major competitive disadvantage.” Read the article

4. The North Star Playbook
John Cutler from Amplitude put together this nice overview of how to define a North Star Metric. Including this checklist with the characteristics of a strong North Star:

  • It expresses value. We can see why it matters to customers.
  • It represents vision and strategy. Our company’s product and business strategy are reflected in it.
  • It’s a leading indicator of success. It predicts future results, rather than reflecting past results.
  • It’s actionable. We can take action to influence it.
  • It’s understandable. It’s framed in plain language that non-technical partners can understand.
  • It’s measurable. We can instrument our products to track it.
  • It’s not a vanity metric. When it changes, we can be confident that the change is meaningful and valuable, rather than being something that doesn’t actually predict long-term success—even if it makes the team feel good about itself.

Read the article

5. The 11 best A/B Testing tools in 2020
… according to Alex Birkett. Read the article

6. Using R to synthesise long-term findings with Meta-analysis at the BBC
Frank Hopkins from BBC’s Experimentation & Optimisation Team writes why meta-analysis of A/B tests are important. And how they do it. Read the article

7. The 2019 State of Conversion Optimization Report
CXL’s fourth edition of the State of Conversion Optimization report. Biggest challenges: better processes and buy-in from decision-makers. Download the full report


Jake quits smoking

Jake Albaugh wants to quit smoking and to help himself along the way, he has created a dashboard that lists the time passed since quitting. And also the benefits of a life without nicotine.


My Favourite Podcasts – 2019 update

Listening to podcasts has gently become a new habit for me.  It is the perfect medium to fill “in-between times” like commutes, exercising, cleaning or ironing.  I use an app called Overcast to listen to my podcasts.

Here are my favourite podcasts – last updated September 2019:

daily thought

Fresh Start Effect

Happy 2019!

I have been reading up on the new year resolutions phenomenon. We all know that everyone starts with new intentions, but a few weeks into the new year, they vanish quickly. We fall back to our old habits.

But for so many people the new year feels like a new start. You can be that better person you always wanted to be. It is called the Fresh Start Effect.

According to the fresh-start effect, people are more likely to take action towards a goal after temporal landmarks that represent new beginnings. Temporal landmarks are days that stand out as being more meaningful than other days and generate a “fresh start” feeling that motivate us to achieve our goals.

And you don’t have to wait for the new year. You can start today. Every day is a chance to start something new or do something to improve.

daily thought

Creative flow

Recently I made my first painting. And I loved the process. It is an activity where you can completely immerse yourself in. And it is something where you are constantly switching state. 

Think of something you can make & make it with your own hands.

Add small details & then take a step back to look at the bigger picture.

Adding stuff & not overdoing it.

I loved it.

When do you experience creative flow?

My First Painting
daily thought

Why I write this blog

3 reasons why I write this blog …

  1. to become a better writer: I believe that training my writing skills every day will eventually make me a better writer
  2. to better understand my own ideas and thoughts. Putting an idea into words forces me to really understand what I am thinking
  3. I love to experiment with different tools. Having my own outlet gives me the opportunity to constantly test out new tools
daily thought

The day there is no news

The 8 o’clock news is always 20 minutes long. Somehow the amount of news is independent of the quantity or impact of the events that happened that day. 

News is relative. On a quiet day, the smallest remark is news. On days of national elections, that natural disaster at the other side of the world will probably stay unnoticed. 

Twenty minutes of news. That is what people expect. That is what has been programmed. That is what has been sold to the ad agency. 

I am looking forward to the day there is no news. The day there is nothing really important to say. The day the news stays quiet. And people can read, play games or just talk with eachother.

“Today there is no news. Have a great evening.”

daily thought leadership

What is important to you?

To know what is important to you at work, try to answer these questions from Seth Godin:

  1. What are you doing that’s difficult?
  2. What are you doing that people believe only you can do?
  3. Who are you connecting?
  4. What do people say when they talk about you?
  5. What are you afraid of?
  6. What’s the scarce resource?
  7. Who are you trying to change?
  8. What does the change look like?
  9. Would we miss your work if you stopped making it?
  10. What do you stand for?
  11. What contribution are you making?

[Original post Seth’s Blog: Ten questions for work that matters]

analytics insights

Best Analytics Newsletters

The field of analytics is changing rapidly. And for many analytics professionals, it is hard to keep up with all new developments. One of the best and easiest things you can do is subscribe to a couple of the best analytics newsletters. From that moment on you will have a constant flow of inspiration, tips, and tricks. Coming straight to your inbox. 

Here are my favourite newsletters on analytics that I recommend everyone to subscribe to. 


Marketing Insights Event – De Impactvolle Data Analist

[DUTCH] Afgelopen donderdag (2 februari presenteerde ik (samen met mijn collega Timothy Dieduksman) bij het Marketing Insights Event in Utrecht. 123 deelnemers namen wij mee in wat een Data Analist kan doen om meer impact te maken. Bij ING zoeken we trouwens nog meer van deze impactvolle Data Analisten!

De presentatie werd gewaardeerd met een 7,9 en vind je hier:


Digital Analytics Conference – De Impactvolle Data Analist

[DUTCH] Afgelopen woensdag (12 oktober presenteerde ik (samen met mijn collega Timothy Dieduksman) bij het Digital Analytics Congres in Utrecht.

Mijn presentatie vind je hier:


Inside the mind of a procrastinator

A funny TED talk by Tim Urban on procrastination. Meet the Rational Decision-Maker, Instant Gratification Monkey and the Panic Monster.

[ted id=2458]


Teletekst: still my favorite newsapp

Teletekst remains very popular in The Netherlands. In other countries (like Great Britain and Belgium) the local Ceefax initiatives have been shutdown. The succes of the Dutch Teletext app can be explained by the fact that the NOS (Dutch Broadcasting Company) released this app in the early days of smartphones.

And here are my three reasons why Teletekst still is my favorite app to follow the news:

  1. Limited: you only have to visit this one page to know what is happening in the world
  2. Speed: one Teletekst page is less than 1 kilobyte
  3. No ads: no annoying advertisements

As long Teletekst exists, I will be using it.


ContentCafé – Het effect meten van content

[DUTCH] Afgelopen woensdag (9 maart) presenteerde ik bij het ContentCafé in Utrecht. Het ging die avond over het meten van het effect van content (marketing).

Mijn presentatie vind je hier:

 [photo credits: Hans Dinkelberg]

Digital Data Tips Tuesday #6

Tuesday 9th of February I presented at Digital Data Tips Tuesday in Amsterdam, The Netherlands. I talked about how you can improve the customer experience with the use of analytics.

You can see the presentation here:



30+ UX Myths that debunk common web design misconceptions

If you read this blog, you probably believe in building websites based on evidence, not false beliefs. If so, then you should read UX Myths – the brainchild of UX designers Zoltán Gócza and Zoltán Kollin.

This is what they say about UX Myths:

Our goal is to provide evidence in user experience design that can help stakeholders move away from design decisions that are based merely on beliefs and personal opinions. But you should still do your own research, check how your design performs.

We’ve collected a lot of research data, as well as facts, quotes and articles from well-known designers and web experts in order to debunk the common web design misconception.

Here are my personal favorite myths:

  1. People read on the web (myth #1)
  2. People don’t scroll (myth #3)
  3. You need to redesign your website periodically (myth #11)
  4. You are like your users (myth #14)
  5. Users make optimal choices (myth #15)
  6. The homepage is your most important page (myth #17)
  7. People can tell you what they want (myth #21)
  8. People are rational (myth #29)
  9. If you are an expert, you don’t need to test your design (myth #30)
  10. Success happens overnight (myth #32)

Read them all at or download this pdf, print it and put them on the wall (a Behance project).

Geen categorie

New Year resolutions

First of all, I wish you all the best in 2016!

If you haven’t made any New Year resolutions yet, here is some advice from Dan Ariely: setup your priorities.

… I get a lot of requests for all kinds of time-consuming activities very day. In general I try to be helpful, but there are only 24 hours of the day and I already don’t sleep much. So, in reality every time I say yes to something I also say no to other things – and my sad realization is that my process for saying yes and no does not lead to a plate of activities that fits with my priorities. So, in 2016 I am going to try and figure out what my priorities are, and then direct my time in a consistent way with my priorities. …

Dan Ariely

So, what are your priorities this year?

[photo credits: Colin Knowles]



Webtrekk User Conference 2015 Berlin

Friday 29th of May I presented at the Webtrekk User Conference in Berlin, Germany. I talked about how you can improve the customer experience with the use of analytics.

I started my presentation with proving the German prejudice of Dutch people driving with caravans is just wrong!

You can see the presentation here:


Newsletter Report February 2015

In February I´ve send 4 Behavioral Insights newsletters. The number of subscribers doubled, so it´s growing steady. Here are the facts and top clicked articles from the February issues.


MIE 2015: Improving Customer Experience using Analytics

Wednesday 4th of February I presented at the Marketing & Insights Event in Utrecht, The Netherlands. I talked about how you can improve the customer experience with the use of analytics.

You can see the presentation – in Dutch – here:


Newsletter Report January 2015

It’s been 4 weeks since my first Behavioral Insights newsletter went out. Time for some facts and an overview of the top links.


Mobile Phone Share of Activations: Pie Chart Remake

Today Consumer Intelligence Research Partners (CIRP) released the results of its research on mobile phone share of activations per manufacturer. You can question the validity of the research, but for now I’ll just assume the numbers are correct. CIRP bases its findings on a survey of (only) 500 US subjects that activated a new or used phone in the October-December 2014 period.

Their main conclusion:


How many people are publicly using Google Plus?

The answer is: somewhere between 4 and 6 million. This is a rough estimation (based on Google’s profile sitemaps) done by Edward Morbius.

I have visualized how the 2.2 billion Google+ profiles break down based on user activity:

How many people are actively using Google Plus? (data: Edward Morbius)


Edward’s findings are:

There are about 2.2 billion G+ profiles.

Of these, about 9% have any publicly-posted content.

Of those, about 37% have as their most recent activity are comments on YouTube videos, another 8% are profile photo changes.

Only 6% of active profiles have any post activity in 2015 (18 days so far).

Only about half of those, 3% of active profiles, are not YouTube posts.

That is, 0.2% – 0.3% of all G+ profiles, about 4-6 million users, have made public post in 2015.

You can find more on this analysis and the method he used in Edward’s Google+ post. There is one caveat: it does not include non-public posts or comments.

The graph is a Sankey Diagram and was made with SankeyMATIC.

[UPDATE] This post got some attention on Reddit, Business Insider, Slashdot, Boing Boing, Twitter and several other sites in HungaryGreece, PolandBrazil and again Hungary.


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Geen categorie

The selfies phenomenon


It’s a strange sight, a group of people taking a photo of themselves. Dan Ariely, behavioral economist, shines some light on the selfie phenomenon:

Geen categorie

30 Days to Data Storytelling


The people of Juice Analytics have created this great 30 Days to Data Storytelling.


It’s critical for analysts and presenters of data to share information in a way that people just get it. Enter data storytelling – a magical elixir to all your data communication woes! Well, maybe not quite. But you should be aware of recent efforts using this timeless approach to deliver information so naturally – through stories.

You should download, print and use it.


New Year’s Resolutions for Photographers


  1. Take more photos
  2. Learn a new skill
  3. Connect with nearby photogs
  4. Save for gear (by selling your photos)
  5. Get in front of the camera
  6. Print more
  7. Brush up on photo history

Read them all at Photojojo

Geen categorie

Unbiased Data


I just love the cartoons from Tom Fishburne. Spot on, as always:

Data doesn’t have biases. It’s people who collect and select the data who bring bias to it. – Tom Fishburne

Geen categorie

Happy New Year!

… and here are ‘5 New Year’s Resolutions That Might Actually Work‘ from Dan Ariely:

  1. Order an annual subscription to the Fruit Guy.
  2. Give a good friend the ability to take some money from your bank account if …
  3. Set up an automatic monthly transfer from your checking account into a savings account.
  4. Set up recurring weekly “meetings” with friends or co-workers for workouts.
  5. Get a dog.

[photo credits: Amodiovalerio Verde]


6+ billion tweets mapped

Eric Fischer made a map of 6+ billion public geotagged tweets. He open sourced the tools he used to manipulate the data: Making the most detailed tweet map ever.

Geen categorie

The Evolution of Experimenting

Today I presented at the Dutch Webanalytics Conference. This was my slide deck (mostly in Dutch):