Manuel Chevalier

@manuelchevalier.bsky.social

Ex-academic data coach helping people who work with data build confident, independent skills in R, using AI to assist rather than replace you. Founder of DataSharp Academy. Here to make data analysis feel natural and doable. More at: datasharpacademy.com

I've often been lured by the word "database". For me, it means clean, structured data, homogenised fields, formal relationships between tables, no (or limited) duplicate rows, etc. When someone tells me they have a database, I instinctively picture a relational database.

Bild

I've started writing my first data science notebook, using the running program I recently started as the excuse to discuss many of the key stages of a typical data science project. Especially the stages that precede the shiny results. Far from the hype, but no less important. 📓 buff.ly/pqOapGq

Running

Sixteen weeks of rebuilding a running routine while documenting every step of a complete data project, from data collection, interpretation, and race time predictions.

manuelchevalier.com

Have you ever wondered what these strange-looking symbols |> or %>% AI keeps spitting really mean? They are actually beautiful things that make your data processing sooo much easier once you get the logic. These pipe operators ( |> or %>% ) can be interpreted as follows: "take the result of the tr

R Fundamentals for Data Science – DataSharp Academy

Learn foundational R skills and discover how to use AI as a supportive tool in your data journey. Whether you’re starting from scratch or looking to

datasharpacademy.com

After the last successful 𝗥 𝗙𝘂𝗻𝗱𝗮𝗺𝗲𝗻𝘁𝗮𝗹𝘀 𝗳𝗼𝗿 𝗗𝗮𝘁𝗮 𝗦𝗰𝗶𝗲𝗻𝗰𝗲 workshop a month ago, I decided to revisit all my slides, exercises, and even my overall outline. As I keep teaching this class, I understand more and more what the participants expect and where they come from.

Bild

Some workflows are so fragile that people become scared of their own folders. “Don’t move that.” “Don’t rename this.” “Don’t touch the old version.” And definitely: “Don’t close RStudio.” If everything breaks the moment something (anything!) moves, your workflow needs more love.

Stop blaming your tools. Start by checking your data. I’ve seen people spend hours rewriting code, changing packages, or asking AI for help… for problems that were quietly sitting inside the dataset from the start. Messy data create fake complexity. => Fix the data, not the pipeline.

The vast majority of coding problems come from: * inconsistent formatting * hidden missing values * broken variable types * messy real-world data You probably know how to code. But are you equipped to deal with the real complexity of data analysis?

One of the biggest shocks in data analysis: Real datasets are NOTHING like tutorial datasets. Inconsistent categories. Broken dates. Missing metadata. Mixed formats. Unexpected NAs. Many people think they are bad at coding. In reality, nobody prepared them for messy data.

Messy data create fake complexity. If adding 1 and 1 gives you 11, don't blame your tool. Your data probably need some love. A dataset with inconsistent categories, mixed formats, incomplete metadata, or duplicated labels can completely distort your understanding of what is happening.

Most “coding problems” are actually data problems. Not the algorithm. Not the package. Not R/Python. Your data! Wrong types. Inconsistent strings. Hidden spaces. Duplicate categories. Unexpected NAs. "1" ≠ 1 "Blue" ≠ "blue" The code is often just reacting to the chaos underneath.

AI can already help you write code. The real challenge is learning how to look at your data: - spotting suspicious patterns - questioning assumptions - understanding what the dataset can actually support That skill is built through experience, not magic.

Bild

1/ One thing that took me years to accept: Good data analysis is often surprisingly slow at the beginning. Not because strong analysts are inefficient. But because they spend time understanding the dataset before deciding what to do with it.

Most people approach data analysis backwards. They first ask: “What method should I use?” But strong analysis starts earlier: - understanding the dataset, - spotting patterns, - questioning assumptions, EDA is the foundation of the analysis itself. Don't skip it.

Most people think exploratory data analysis means loading a dataset and making a couple of plots. But EDA is about learning how your data behave: - what looks suspicious - what moves together - what is missing Otherwise, you risk solving the wrong problem with the wrong method.

You load a dataset. Sometimes you don’t know where to start. Other times you think you do… until nothing makes sense. Your problem is a lack of structure. Start simple to make things click • What are you trying to answer? • Can your data support it? • What are the key steps? datasharpacademy.com

Confident Data Analysis with DataSharp Academy

We offer practical, hands-on data analysis foundational training to help you structure, analyse, and communicate data with clarity and confidence.

datasharpacademy.com

Thinking “I’ve seen this before, I know how to handle this” is often where the problem starts. You stop looking at the data, and start fitting it into what your expectations. And just like that, the analysis is already biased. Never forget each project demands specific tools and care.

Have you ever found yourself just "doing stuff" with your data? You were asked to analyse them, so here we are. RStudio is open. Some fancy graphs. It looks like work. But what are you _really_ trying to do? How should you analyse them? And most importantly, why?