Assignment # 1

Good and Bad Visualization

Ying Zhang

A good example of visualization

Source: http://www.baltimoresun.com/news/health/bal-te.dna23feb23,1,2965177.story?page=3&coll=bal-health-storyutil&ctrack=1&cset=true

What does this picture show?

The picture of good visualization: the picture shows the structure of a DNA molecule. It illustrates a DNA molecule consisting of two strands that are parallel to each other and together forming a spiral shape. Inside the double-strand structure, there exists four types of nitrogenous bases, and each two of them forms a pair. One pair formed only between adenine (A) and thymine (T), and the other pair is formed only between guanine (G) and cytosine (C).

Critique of the visualization: This is a good visualization of the structure of a DNA molecule. The picture precisely illustrates the shape of a DNA molecule and the nature of DNA formation. It also uses the metaphor of two ribbons to indicate the backbones of a DNA molecule are formed by sugar-phosphates bonding together. Inside a DNA strand, four different nitrogenous bases are clearly differentiated using four different colors with the abbreviation of each base’s name labeled. As a student who took biology 111, I received a graphical sense of how a DNA is actually formed and what chemicals are present in the formation of so-called double-helix.

A bad example of visualization

Source: Biology Fourth Edition: Cambell Page: 90

What does this picture show?

This is a picture showing some metabolic reactions that happens in a cell. The dots represent molecules present in a cell, and the lines represent the chemical reaction that transform from one kind of molecule to another.

Critique of the visualization: This visualization is extremely confusing and ambiguous. Since there is no indication of the name of each molecule (black dot), and there is no indication of the name of each chemical reaction that transform one molecule from one type to another. Plus, since those reactions happen inside a cell, there is no clear visual boundary definition of a cell organelle. By presenting the picture itself without any labeling, its content has complete no meaning other than clusters of dots and lines connecting to each other. As a student taking biology 111, I don’t understand the purpose of presenting this picture as a useful figure in the source textbook.