diff --git a/presentations/software-engineering-basics/software-engineering-basics.pdf b/presentations/software-engineering-basics/software-engineering-basics.pdf
index 6bc635c..84a213b 100644
Binary files a/presentations/software-engineering-basics/software-engineering-basics.pdf and b/presentations/software-engineering-basics/software-engineering-basics.pdf differ
diff --git a/presentations/software-engineering-basics/software-engineering-basics.tex b/presentations/software-engineering-basics/software-engineering-basics.tex
index da32860..30e9aed 100644
--- a/presentations/software-engineering-basics/software-engineering-basics.tex
+++ b/presentations/software-engineering-basics/software-engineering-basics.tex
@@ -195,6 +195,7 @@ Namespaces are one honking great idea -- let's do more of those!
 \end{frame}
 
 
+\section{Falsehood Data Scientists Beliefes}
 \begin{frame}{Falsehood Data Scientists Beliefes}
 \begin{centering}
 (1) Floating point numbers always look like this: 1.23456 or 0.000004577 or 12345.467765.
@@ -280,6 +281,21 @@ Namespaces are one honking great idea -- let's do more of those!
 \end{frame}
 
 
+\begin{frame}{Falsehood Data Scientists Beliefes}
+\begin{centering}
+(5) The (physical) unit of a column / an API can be guessed.
+\end{centering}
+
+\uncover<2->{
+    \begin{itemize}
+        \item<2-> Clarify it
+        \item<3-> See if the distribution / quantiles are reasonable
+        \item<4-> Internally, use unit library \href{http://pint.readthedocs.io/en/latest/}{Pint}
+    \end{itemize}
+}
+\end{frame}
+
+
 \begin{frame}{See also}
     \begin{itemize}
         \item git