Another important information structure often used in technical writing is the discussion of causes and effects.

What Is a Cause–Effect Discussion?

Discussions like these answer questions such as the following:

Note: See the complete example of a causal discussion.

Some examples:

As you can see from these examples, we can discuss the causes and effects of human or social processes, natural processes, mechanical or physical processes, historical or economic processes, meteorological or biological processes, and on and on.

If you think about it, there's not much difference between process discussion and causal discussion. Both occur over time; steps in a process often involve causes and effects. The distinction depends on your purpose and emphasis: process discussions are primarily concerned with how an event occurs; causal discussions, with why an event occurs. Process discussion focuses on the chronology of something; causal discussion focuses on the causes and effects.

For some topics, however, such as explaining tornadoes, it's almost impossible to make a distinction. Here are some contrasting examples:

SubjectProcess discussionCausal discussion
Lightning How to safeguard home appliances from lightning What natural phenomena cause lightning
Instruction writing How to set up understandable instructions What causes instructions to be unclear
Acquisition of language by childr enrapidly How to help children learn language more rapidly Why certain children learn language more rapidly
Growing tomatoes How to plant and care for tomatoes Reasons why tomatoes are less productive
Air conditioning How cool air is produced by conventional systems Why your air conditioning is costing you more this summer

Here are some common reasons why you may need to discuss causal and effects:

How to Organize Causal Discussions?

How you organize the contents of a causal discussion depends on how many and what combination of causes and effects you discuss:

Organization of effects in a short causal discussion. First, the cause is stated; then the effects are discussed one after another.

Consider a simple example: imagine you want to discuss how a single situation has led to a number of problems, in other words, one cause leading to several effects. In a single paragraph, the first couple of sentences might focus on the cause; each of the following sentences would focus on the effects. In an extended discussion, there might be a paragraph on the cause, and a paragraph on each of the effects. The preceding schematic diagram of a causal discussion in shows you how the single-paragraph approach would look.

How to Discuss Causes and Effects?

Actual discussion of causes and effects is not as immediately identifiable as descriptive or process writing are. Typically, causal discussions talk about events and describe things. What makes causal discussions distinctive is the use of transitional words to indicate the causes and effects.

In this sentence:

Increased deficit spending by the government leads to increased inflation

the verb "leads to" establishes the connection between a cause and an effect. In this excerpt, the connective "consequently" establishes a causal link between the increasing domestic anger over the Vietnam war and Johnson's decision not to seek reelection:

Meanwhile at home, anger, hostility, and outright revolt against the war grew. Johnson, sensing he could not get reelected in this atmosphere, consequently decided against running for another term.

Cause–effect relationship involving a single effect followed by an extensive exploration of its cause.

How to Format for Causal Discussions?

Here are a few suggestions on format as they relate specifically to causal discussions:

Schematic view of cause–effect discussions. Remember that this is just a typical or common model for the contents and organization—many others are possible.