I am a technical leader, senior software developer and writer interested in the online industry. • Email: rafalrybnik@yahoo.com

Make data your unfair competitive advantage

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Conjoint analysis is based on the idea the relative attributes and their levels considered jointly can be measured better than when considered in isolation. (fig. by author)

Conjoint analysis is a market research method used to measure customer preferences and the importance of various attributes of products or services. In this method, products or services (real or hypothetical) are presented to respondents (e.g. potential consumers) as a set of profiles. Each profile is described by attributes and their levels. Those attributes and their levels are explanatory variables. On the basis of the collected assessments (preferences) from consumers, a breakdown (decomposition) of total preferences is made, using statistical methods, by calculating the share of each attribute in the estimated total utility of the profile.

This way, marketers can identify which combination of attributes is going to perform on the market or which will be the most sought after combination in terms of the consumer’s point of view before actually introducing a new product. …


Why cashiers ask for your postal code when you pay using a credit card

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(Fig. by Author)

Storage-based methods (described in the previous part) are the best-known and the most-used methods for identifying and tracking people online.

Why not only storage-based

However, these methods sometimes do not affect. Users can easily turn off or clear up browser storages. Browsers also develop methods to restrict the possibility of tracking.

Device or browser fingerprinting is to solve those issues.

Why the cashier needs my postal code

Do you know why cashiers often ask for postal code, when you pay using a credit card?

It happens because retailers want to attribute what shopping baskets are bought by a particular consumer. The shop does not obtain all digits of your credit card number, but only a few last digits. …


Choice-Based Conjoint Analysis

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In choice-based conjoint analysis, a set of products is presented to consumers in a similar manner to the real marketplace situation. They decide which one is the most attractive for them. (fig. by author)

In the previous article, I introduced a conjoint analysis and provided some examples of how useful the market research method is. I recommend you to read it first.

Choice-based conjoint analysis (CBC, or: discrete choice modelling, discrete choice experiment, experimental choice analysis, quantal choice models) uses discrete choice models to collect consumer preferences. The main difference distinguishing choice-based conjoint analysis from the traditional full-profile approach is that the respondent expresses preferences by choosing a profile from a set of profiles, rather than by just rating or ranking them. …


Advice from Google’s chief economist

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Hal R. Varian, Google’s Chief Economist (pic. source)

Interesting data science project in a portfolio could not only validate your skills but also help find a job. Beginner data scientists often struggle to come up with ideas for their next project.

But there is a way to find ideas and to determine that they are worth time.

Dr Hal R. Varian is the Chief Economist at Google and also an emeritus professor at the University of California, Berkeley. Maybe some of you, who studied economics, recognize him as the author of economics textbooks.

In the mid-nineties, Varian described his method of making economic models in the popular essay. …


Working on Machine Learning models or big data processing means a lot of waiting.

While I work on scraping data from a website or train machine learning model, it happens that I am not sure that the script is still working.

It will be good to have an indicator that the script is executing, just like old Windows hourglass cursor.

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Windows hourglass cursor (source)

There is a handy package for this task called yaspin (Yet Another Terminal Spinner for Python).

Example of spinner (by author)

To install it, just use old good pip:

pip install yaspin

When the package has been installed, it’s usage is pretty straightforward. …


Törnquist function and econometric analysis of demand

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Photo by Erik Mclean on Unsplash

The relationship between the households’ demand for certain goods and their income interests economists for a long time.

We intuitively understand that when one’s income is increasing, so does his or her consumption.

But the demand for some goods is independent of people’s income.

There are also goods, however essential, that does not increase the share of expenditure, even if households income increases.

Except in extraordinary circumstances, the rich do not buy all the toilet paper and canned food from the market.

Necessity goods

In common sense, necessity good is usually defined as an indispensable thing, something that everyone needs.

Necessity goods are the last things that consumers stop buying when their income declines. …


Last proposition of Web Neural Network API for better web performance

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(fig. source)

What if a website would be able to predict your preferences and adjust its appearance to maximize your experience?

Or if a web-based video conferencing application could replace a messy room with another background and cancel noises of your dog?

We already have the technology.

Thanks to JavaScript machine learning frameworks, such as Tensorflow.js or ONNX.js, we can easily implement these functions in the web environment.

However, they have one disadvantage — poor performance in comparison with native apps.

Neural hardware

Hardware architectures specialized for machine learning purposes emerged because of increasing demand for computing capabilities.

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Progress in computing capabilities and web application do not always go hand-in-hand (fig. by Author)

Since 2017 (release of iPhone 8), Apple implements hardware support for neural networks in iPhone and iPad processors. Other platforms develop their own solutions as well. …


Every day is a weekend day when you are stuck at home

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Woman Working At Home Using Her Laptop (Vlada Karpovich, Pexels)

Due to the COVID-19 pandemic, a hundred millions around the world were forced to stay at home (by governmental lockdowns or for worries about their health).

Thus, more people depend on private Internet connectivity, for work, education, social activities, entertainment and formalities.

In a recent study (accepted for Internet Measurement Conference 2020, preprint on arXiv) researchers use data from Internet providers to see how user behaviour has changed.

In March, Internet traffic of users increased by 15–20% almost within a week.

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Initial lockdowns triggered changes in Internet traffic. (Figure based on the original study)

Not only the volume of traffic but also its distribution over the day has changed.

During the lockdown, daily patterns at workdays have become more similar to those on weekend days. …


Part one

Cross-domain tracking without using third-party cookies

Cookie bakery

Modern Web is the cookie bakery. Advertisers use cookies to serve creepy ads. Website owners use cookies to measure their audience. Developers use cookies for store user settings.

Gosh, even those cookie information pop-ups are cookie-based (how would otherwise a website know you have already seen one?).

Video fragment of asdfmovie5

Since the invention of mighty cookies, the whole industry is relying on the ability to track website users. And third-party cookies are the most popular mechanism used by advertisers to identify the user between domains.

So no wonder, this mechanism is under discussion. Due to privacy concerns.

Google cookie monster

In August 2019 Chrome’s team announced that they are going to drop third-party cookies from their browser within 2 years. Chrome is the last browser to start working on the restriction of third-party cookies. …


Nothing. It was fake news.

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Stock photo from Canva

A few weeks ago, social media users claimed that the US National Park Service was feeding watermelon to bee colonies.

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It seemed suspicious to me from the beginning.

Watermelon does not seem to have much nutritional value.

In addition, wild animals would become interested in the fruit quickly enough so that bees would not be able to benefit from it at all.

As I do not have much knowledge of bees, I have looked for experts in this matter.

I was not only interested in answering the question of whether this is happening.

I wanted to know whether the effect shown in the photo is at all possible. …

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