1  Why study applied stats?

Statistics are everywhere

A general approach to answer questions with data.

Central to experimental sciences, e.g. biology, psychology, physics

Fundamental to experimental science

Biology, medicine, physics, you name it!

Consider the following questions:

Business and politics also heavily rely on statistics to make decisions (hopefully!).

NoteIn-class activity

In Figure 1.1, six newspaper articles answer a simple question using a statistical approach.

What would you answer off the top of your head? Does the article agree or disagree?

“Can’t I just use AI?”

In the last two decades, statistics has increasingly become known under other names: data science, machine learning, artificial intelligence. These fields all rest on the same statistical foundations — AI doesn’t replace statistical thinking, it’s built on it.

1.1 A worked example: Foramitti et al. (2025)

To fix ideas, let’s focus on one study: Foramitti et al. (2025) analyzed the sentiment of US Billboard song lyrics from 1973 to 2023.

In the statistical parlance:

Similarly, supporting H2a, the monthly average sentiment in popular music lyrics correlated negatively with time (r = −.78, 95% CI [−0.81, −0.75], p < .001).

around the onset of COVID-19 in the US, the analysis yielded a lower adjusted of 0.475. Here, we found a small but significant interaction period × time (β = −0.007, 95% CI [−0.011, −0.003], t(49) = −3.626, p < 0.01) (Supplementary Table S5, Figure S3). However, this effect points in the opposite direction as hypothesized initially.

In plain English:

  • Songs are sadder with time
  • Songs are not always sadder after societal crises

1.2 Statistical analysis is a journey

From question → data → statistics → conclusions.

It requires complex technical tools, domain knowledge, and critical thinking.

The reward: a clear and adequate representation of the world — which brings joy (or empowerment, an increase in ability, …).

Foramitti, Markus, Urs Markus Nater, Claus Lamm, and Maurício Martins. 2025. “Societal Crises Disrupt Long-Term Increases in Stress, Negativity, and Simplicity in US Billboard Song Lyrics from 1973 to 2023.” Scientific Reports 15 (1). https://doi.org/10.1038/s41598-025-28327-5.