buy levitra


What is most useful to you? You may select more than one answer.

View Results

Loading ... Loading ...

Arts & Letters Daily


Essay: Deductive Reasoning

Deductive Reasoning

Deductive Reasoning

     Dr. Otto

YouTube Tutorial – click HERE
PowerPoint Writing Tutor 16 – Deductive Reasoning
Text for Tutorial – click HERE.
Sample – scroll down to Sample
Assignment – scroll down to Assignment
Answer Key – scroll down to Answer Key
Practice oral English – click HERE


In information text, readers look for two things: reliable information based on evidence and logical arguments. When readers sense that the information is not reliable, suspicion sets in. If the arguments do not fit together logically, they are not convincing even when the information seems correct.

The most familiar argument for readers is based on factual premises which lead to a factual conclusion. The arguments become more complicated when factual and value premises are mixed.

The Basic Model for Deductive arguments

Reasonable arguments flow from facts to conclusions in two basic ways – deductively and inductively. Inductive arguments start with evidence that leads to a conclusion. The basic form of deductive arguments is the syllogism which is a three part set of assumptions that contain two premises and a conclusion.

Factual premise:

Factual premise:




Factual Premise or statement  –             Whales are mammals

Factual premise  or statement – All mammals suckle their young

_____________________      ____________________

Factual conclusion –                   Whales suckle their young

In deductive arguments, the premises contain all the information contained in the conclusion. The conclusion cannot include any information not contained in the premises.

The strength of a deductive argument rests in its premises. If readers accept the premises, they usually grant the conclusion. Hence, the key is to get readers to accept the premises. This is done by presenting evidence supporting the premises.

The conclusion of a deductive argument must follow logically from the premises. For the conclusion to be true, both premises must be true. The conclusion may appear at the beginning or the end of a paragraph or report. If the conclusion is likely to be accepted by readers, it could be placed at the beginning.

These notes address only deductive arguments based on facts. There are two variations on it. First, a deductive argument can be based on a factual premise and a value premise. Second, a deductive argument can be based on two value premises. In both cases, the conclusion is always a value conclusion.


Red River Valley Flood

In the winter of 1993-94, The Red River Valley received record amounts of snow. Fargo reported 89.1 inches when the average annual snowfall is 35-40 inches. The Valley did not experience a disastrous flood. In 1996-97, Grand Forks received 98.6 inches of snowfall and experienced disastrous flooding. Why? The only explanation offered by climatologists is the melt rate factor. Fargo experienced a slow melt rate in 1993-94 because the warm days were followed by cold nights when much of the water became ice. Hence, water accumulated slowly and no serious flooding occurred. In contrast, Grand Forks experienced warm weather, up in the 50’s without freezing night time temperatures. Run-off water was generated at a fast rate because of the rapid melt rate. The result was a disastrous flood.

Template for deductive reasoning

Factual premise or statement – record amounts of snow

Factual premise or statement – slow melt rate

_____________________      ____________________

Factual conclusion – no serious flooding


Assignment: Deductive reasoning

Read the following report and identify the deductive reasoning presented in the report.

Literacy and the Internet

Literacy continues to be important to achieve, but difficult to learn and difficult to teach. This is even more critical today since literacy includes not only the ability to read, write, speak, listen, and compute but also to think critically and to learn on one’s own. A brief review of the approaches currently taken to improve literacy in senior high schools would suggest that new approaches need to be explored. One of these new approaches is the use of the Internet because it provides learner with a rich interactive learning environment. Hence, I am presenting an argument for the use of the Internet to help students improve their literacy skills.

Two approaches have been used traditionally at the senior high level to address literacy. One approach is to teach academic survival skills while focusing primarily on vocational education to help students learn a specific skill or trade. The second approach is to provide broad-based remediation of academic skills.

Providing vocational education with some academic survival skills is not likely to meet the changing needs of young people in a rapidly changing society because such training is too narrow. As never before, students face a rapidly changing society in which they have to find employment requiring strong literacy skills. The problem with an academic remediation approach is that often it provides the same type of instruction that was unsuccessful in the first place. It is unsuccessful with many students probably because it does not provide a meaningful context for acquiring the skills. Remediation has sometimes been referred to as “drill and kill”.

More recently, several new applications of technology have been used to address literacy in schools. The use of computers for word processing was introduced to encourage students to write more; it was followed with the introduction of applications including writing organizers and publishers. Some students showed some improvement with the use of these applications but many continued to experience serious writing problems. Laser disks and CD ROMs were introduced to improve students’ reading and research skills. The limited number of available educational resources on laser disks and CD ROMs makes it difficult to assess their impact on students’ literacy.

There is good reason to believe that the use of the Internet could help to improve students’ research and communication skills. It can be used to connect students around the world with each other and to resource people in universities and the workplace. Through these networks, students can access information on most topics. Given the importance of an audience for learning to speak, listen and write, this application of technology needs to be explored in schools for improving students’ literacy skills. Limited research is available on the impact of the Internet on education because high speed Internet access has been available to students only in recent years.

Due to the limited success of past practices for improving literacy, researchers need to study the impact of current technology, especially the Internet, on improving student’s research and communication skills.

Deductive reasoning

Factual premise or statement     –

Factual premise or statement    –

_____________________             ____________________

Factual conclusion                   –


Writing Assignment: Deductive Reasoning

Write a paragraph in which you use a deductive argument on a topic of your choice. Submit it to your instructor or tutor for feedback on grammar and your deductive reasoning. Then edit your paragraph based on the feedback you received.

Complete the template for  Deductive Reasoning on your paragraph.

Deductive reasoning

Factual premise or statement –

Factual premise or statement –

_____________________             ____________________

Factual conclusion                   –

Answer Key

Deductive Reasoning – Literacy and the Internet

Factual Premise the Internet can be used to connect students around the world with each other               and to resource people in universities and the workplace

Factual premiseThrough these networks, students can access information on most topics.

________________    _____________________________________________________

Factual conclusionThere is good reason to believe that the use of the Internet could help to improve students’ research and communication skills.