Hospital statistics regarding people who go to the emergency room after roller-skating accidents indicate the need for more protective equipment.  Within this group of people, 75 percent of those who had accidents in streets or parking lots were not wearing any protective clothing (helmets, knee pads, etc.) or any light-reflecting material (clip-on lights, glow-in-the-dark wrist pads, etc.).  Clearly, these statistics indicate that by investing in high-quality protective gear and reflective equipment, roller skaters will greatly reduce their risk of being severely injured in an accident.  

Although the argument stated above discusses the importance of safety equipment as significant part of avoiding injury, the statistics quoted are vague and inconclusive.  Simply because 75 percent of the people involved in roller-skating accidents are not wearing the stated equipment does not automatically implicate the lack of equipment as the cause of injury.  The term "accidents" may imply a great variety of injuries.  The types of injuries one could incur by not wearing the types of equipment stated above are minor head injuries; skin abrasions or possibly bone fracture of a select few areas such as knees, elbows, hands, etc. (which are in fact most vulnerable to this sport); and/or injuries due to practising the sport during low light times of the day.  During any physically demanding activity or sport people are subjected to a wide variety of injuries which cannot be avoided with protective clothing or light-reflective materials.  These injuries include inner trauma (e.g., heart-attack); exhaustion; strained muscles, ligaments, or tendons; etc.  Perhaps the numbers and percentages of people injured during roller-skating, even without protective equipment, would decrease greatly if people participating in the sport had proper training, good physical health, warm-up properly before beginning (stretching), as well as take other measures to prevent possible injury, such as common-sense, by refraining from performing the activity after proper lighting has ceased and knowing your personal limitations as an individual and athlete.  The statistics used in the above reasoning are lacking in proper direction considering their assertions and therefore must be further examined and modified so that proper conclusions can be reached.  

Commentary  

This adequate response targets the argument's vague and inconclusive "statistics."  The essay identifies and critiques the illogical reasoning that results from the misguided use of the argument's statistics:  

-- that non-use of equipment may be "automatically" assumed to be the    cause of injury 

-- that "accidents" may refer to minor injuries 

-- that injuries may result from other causes -- skating in the dark,    failure to train or warm-up properly, failure to recognize one's    physical limitations  

The writer competently grasps the weaknesses of the argument.  The ideas are clear and connected, but the response lacks transitional phrases.  Development, too, is only adequate.  

Control of language is better than adequate.  The writer achieves both control and clarity and ably conforms to the conventions of written English.  Overall, though, this 4 response lacks the more thorough development that would warrant a score of 5.