It’s fun to read about novel information. Although “information” often reminds us of concrete facts like numbers or events, we actually expect to see other information when reading. One such information is the logical connection between the concrete facts.
One type of logical connections that many people expect to read is causality. Humans are attracted by causes and effects: scientists ask about the causes of observations; engineers use the effects of techniques to build systems; besides adults, even young children are attracted by causal information — remember how often kids ask “Why?”*
As causal information is generally interesting, people would also enjoy gaining such knowledge while reading. So when writing an article or telling a story, it can potentially** make a difference if we explain not only concrete facts but also how the facts affect each other. For example, writers can aim to explain “why” questions like why an evidence supports an argument and why two arguments are mentioned together. When an article answers these questions better, readers may enjoy the article more. Example:***
- “We first built system A, which is good. We then built system B, which is an extension from A and even better.”
- “We first built system A, which is good. We then built system B, which extends A’s functionality X and is better at doing Y.”
Snippet 2 is clearer, explaining why B extends A and why B was better than A. This causal knowledge in itself can be interesting for some readers, even if they didn’t care much about A and B. When readers feel that they learned something, they remember the story better. On the other hand, snippet 1 omits this causal information. This omission makes the story just a sequence of chronical events, which can appear irrelevant or unimpressive to some readers.
Besides causality, also important are other types of logical connections such as contrast, addition, and enumeration. When writing, we can potentially** improve the readability by making these connections more explicit and easier to grasp. Example:
- “We found phenomenon A, which indicates X. We also found phenomenon B, which indicates non-X. Factor C played an important role in determining X.”
- “We found phenomenon A, which indicates X. We also found phenomenon B, which indicates non-X. We attribute the inconsistency between these two findings to factor C.”
Snippet 2 is clearer, stating explicitly the contrast between A and B. This explicit connection can help readers understand why C appears in this discussion. On the other hand, snippet 1 is implicit about this connection. So it becomes the readers’ job to summarize the connections between A, B, and C by parsing the surrounding text. When sentences grow longer in practice, readers may not have large enough memory to achieve it easily. The readers would then need to read the surrounding text painfully for multiple times, just to figure out what the author implies by introducing C.
Note that adding conjunctive adverbs or transitional words — though sometimes helpful — is often insufficient in making the logical connections explicit. Example:
- “Previous studies have done A. We did B. However, our findings are consistent with previous studies.”
- “Previous studies have done A. We did B. Despite the different methods, our findings are consistent with previous studies.”
Snippet 2 is clearer. It clarifies that “different” methods are in contrast to similar results. On the other hand, snippet 1 is unclear about what the contrast is. Since the readers are left with incomplete information, they are free to guess what the author means. A reader might unfortunately guess, for instance, that the current study has some strange problems that somehow made its findings hard to explain.
* Children look satisfied when they figure out causes, purposes, or reasons. A recent study also found that preschoolers worked longer if they learned about the purposes of new objects as rewards. This causal information was more motivating than novel facts and stickers. For example, the preschoolers worked longer when they learned that a novel item “is used to make food mushy” (object purpose) and worked shorter when they learned that the novel item “always has mushy food inside” (mere facts). These two descriptions had comparable cognitive load, but conveyed different information. The first description has more causal information than the second one. Apparently, children find it quite interesting and even rewarding to learn about causal information. Though studies on children don’t always apply to adults, it seems reasonable here to say that adults are also attracted by causal information to some extent.
** Different readers might appreciate this information differently and react differently to the lack of this information. For example, I seem to be bothered a lot when a story omits causal information. Before knowing the underlying causes or reasons, I forget quickly; after knowing such information, I can easily remember new facts for a long time. A friend of mine, however, is almost the opposite. She is surprisingly good at memorizing random facts; she seems to be happily productive even without knowing “why.” Our different preferences in information have led us to different hobbies and careers. She loves humanities, while I enjoy engineering.
*** These examples are abstracted from my friends’ essays or papers.
 Asher, Y. M., & Nelson, D. G. K. (2008). Was it designed to do that? Children’s focus on intended function in their conceptualization of artifacts. Cognition, 106(1), 474-483.
 Alvarez, A. L., & Booth, A. E. (2014). Motivated by meaning: Testing the effect of knowledge‐infused rewards on preschoolers’ persistence. Child development, 85(2), 783-791.