In my last column I wrote about literal comprehension and some ways to improve students' factual understanding of passages. But not all reading comprehension is literal. Sometimes the understanding of a passage requires inference. That leaves many students and instructors scratching their heads.
Inference in Comprehension
Inferential questions require that the student have some knowledge about the relationship between two or more objects or events. Sometimes that relationship is clearly stated in the material (e.g. "The faster you drive, the greater the risk of an accident.") Most often the relationship is not stated with such clarity. In cases where the relationship is not explicitly stated, the student is expected to know the relationship or is expected to infer the relationship from the information provided.
When the Relationship Is Explicitly Stated
Much textbook material is designed to be expository, to convey specific information. That is often done with key sentences that explain the relationships between events or items. To improve comprehension, the instructor points out the information that states the relationship and then asks questions about "what if" or "why." Consider the following paragraph:
All of the research that has been published about accidental death and injury in road accidents points to the fact that speed kills. More people are killed or injured in automobile accidents than in plane crashes. In almost 75% of all vehicle accidents at least one of the drivers was traveling faster than the posted speed limit. Speed in high-density areas only increases the odds of someone being injured or killed by an automobile...
Some Good Follow-Up Questions
- What if I drive at 60 miles an hour on an interstate highway?
- What if I drive 60 miles an hour on the main street of town?
- Which situation is more likely to result in an accident?
- Teach the students to isolate the key sentence or sentences which define the relationship between the objects or events.
- Model the process with a number of examples from various passages.
- Help the student to find key sentences.
- Allow the student to find the key sentences by themselves.
- Confirm that they are correct.
There are other factors which make the task more difficult. One of these is the degree to which the pieces of relevant information are separated from each other. If one bit is several paragraphs or pages back from the rest of the relevant information, it is more easily missed or forgotten. If the relevant information is in the same paragraph or at least nearby, the student has a much greater chance of finding or remembering it.
When working with long assignments, try making notes or using a highlighting marker to make relevant statements stand out. Students can refer to their notes or highlights more quickly than trying to reread many passages.
The number of distractors that appear in the passage also make finding the key statement more difficult. Distractors are those sentences which do not relate closely to the subject at hand. In the paragraph above, the statement that more people are killed in automobile accidents than in airplane crashes is not really relevant to the issue of speeding. It is this interesting but irrelevant information that could distract some students from the idea that excess speed is more likely to result in accidents.
- During instruction, ask the student if a particular sentence tells them more about the topic at hand or not.
- Ask the student to find a distracting sentence in a passage.
- Determine what makes the sentence distracting.
Such questions help students to learn to spot distractions in passages and to ignore them.
When the Relationship Is Not Stated
The situation becomes more difficult for students when the information assumes that the student understands a relationship between the facts and when this relationship or the facts are not given. In social studies, for example, the student may be asked about national security. Sufficient information about security factors, such as illegal entry issues, may not be included in the information. Consider the following paragraph:
Since the terrorist attacks of September 11, 2001, there have been significant measures taken to make sure that American borders are safe and secure. The Department of Homeland Security has been established. A system of levels of alerts has been created. Airports have more metal detectors and more security personnel to search for weapons and explosives. Trucks and ship containers are scanned more frequently and more carefully as they enter the country. Individuals crossing at U.S. border points are more carefully scrutinized to detect false passports and visas used to gain entrance illegally.
Then the student is asked to answer various questions (e.g. Which border do you think has tighter security? The US/Canada border or the US/Mexico border?) There is no specific information in the passage that relates to this question. The question assumes that the student knows other relevant information.
- Preview the information to see if the necessary facts are stated.
- Teach the information that is missing.
- Describe the relationship between the events or objects.
- Check to see that the student can state the relationship.
If we expect students to learn inferences, we have to ensure that the relationship between objects and events becomes known to them. If the information regarding that relationship is provided in the passage, we need to make sure that they can find it. If the information that will allow them to understand the relationship is missing, we have to provide it as part of the instruction. Our first task involves previewing the passages they are reading to determine if the relationship is stated or not. Just doing that simple task makes it much easier for us to know what is missing and must be taught. This is vital for students to learn the connections that help them to understand passages.