三、逻辑问题例文分析

Case Study 1：

The following appeared as part of an article in a daily newspaper.

    “The computerized onboard warning system that will be installed in commercial airliners will virtually solve the problem of midair plane collisions. One plane’s warning system can receive signals from another’s transponder--a radio set that signals a plane’s course--in order to determine the likelihood of a collision and recommend evasive action.”

   Discuss how well reasoned you find this argument. In your discussion be sure to analyze the line of reasoning and the use of evidence in the argument. For example, you may need to consider what questionable assumptions underlie the thinking and what alternative, explanations or counterexamples might weaken the conclusion. You can also discuss what sort of evidence would strengthen or refute the argument, what changes in the argument would make it more logically sound, and what, if anything, would help you better evaluate its conclusion.

 2分作文:

     This argument has no information about air collisions. I think most cases happen is new airports because the air traffic is heavy. In this case sound airport control could solve the problem.

     I think this argument is logically reasonable. Its assumption is that plane collisions are caused by planes that don’t know each others positions. So pilots can do nothing, if they know each other’s position through the system it will solve the problem. If it can provide evidence the problem is lack of knowledge of each other’s positions, it will be more sound and persuasive.

      More information about air collisions is helpful, (the reason for air collisions)

4分作文

The argument is not logically convincing. It does not state whether all planes can receive signals from each other. It does not state whether planes constantly receive signals. If they only receive signals once every certain time interval, collisions will not definitely be prevented. Further if they receive a signal right before they are about to crash, they cannot avoid each other.

     The main flaw in the argument is that it assumes that the two planes, upon receiving each other’s signals, will know which evasive action to take. For example, the two planes could be going towards each other and then receive the signals. If one turns at an angle to the left and the other turns at an angle to the right, the two planes will still crash. Even if they receive an updated signal, they will not have time, to avoid each other.

The following argument would be more sound and persuasive. The new warning system will solve the problem of midair plane collisions.  Each plane will receive constant, continual signals from each other. If the two planes are headed in a direction where they will crash, the system will coordinate the signals and tell one plane to go one way, and the other plane to go another way. The new system will ensure that the two planes will turn in different directions so they don’t crash by trying to prevent the original crash. In addition, the planes will be able to see themselves and the other on a computer screen, to aid in the evasive action.

 6分作文：

The argument that this warning system will virtually solve the problem of midair plane collisions omits some important concerns that be addressed to substantiate the argument. The statement that follows the description of what this warning system will do simply describes the system and how it operates.  This alone does not constitute a logical argument in favor of the warning system, and it certainly does not provide support or proof of the main argument.

   Most conspicuously, the argument does not address the cause of the problem of air plane collisions, the use of the system by pilots and flight specialists, or who is involved in the midair plane collisions. First, the argument assumes that the cause of the problem is that the planes’ courses, the likelihood of collisions, and actions to avoid collisions are unknown or inaccurate. But if the cause of the problem of midair plane collisions is that pilots are not paying attention to their computer systems or flight operations, the warning system will not solve the collision problem. Second, the argument never addresses the interface between individuals and the system and how this will affect the warning system’s objective of obliterating the problem of collisions. If the pilot or flight specialist does not conform to what the warning system suggests, air collisions will not be avoided. Finally, if planes other than commercial airliners are involved in the collisions, the problem of these collisions cannot be solved by a warning system that will not be installed on non-commercial airliners. The argument also does not address what would happen in the event that the warning system collapsed, falls, or does not work properly.

Because the argument leaves out several key issues, it is not sound or persuasive. If it included the items discussed above instead of solely explaining what the system supposedly does, the argument would have been more thorough and convincing.