how does a double blind experiment work

HESI LPN

LPN Nutrition Practice Test

1. How does a double-blind experiment work?

A. Both subject groups take turns receiving each treatment.
B. Neither subjects nor researchers know which subjects are in the control or experimental group.
C. Neither group of subjects knows whether they are in the control or experimental group, but the researchers do not know.
D. Both subject groups know whether they are in the control or experimental group, but the researchers do not know.

Correct answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

2. In what units are energy measurements expressed by most scientists and nutritionists outside the United States?

A. newtons
B. liters
C. kilojoules
D. kilocalories

Correct answer: C

Rationale: Kilojoules are the standard units of energy used by most scientists and nutritionists worldwide. Newtons are units of force, liters are units of volume, and kilocalories are more commonly used in the United States but not as widely adopted internationally for energy measurements. Therefore, the correct answer is 'kilojoules.'

3. What is the primary intervention for a child experiencing a tonic-clonic seizure?

A. Administer intravenous fluids
B. Place the child in a prone position
C. Protect the child from injury
D. Perform mouth-to-mouth resuscitation

Correct answer: C

Rationale: The primary intervention for a child experiencing a tonic-clonic seizure is to protect them from injury. Placing the child in a prone position can be dangerous as it may lead to further harm due to the risk of aspiration or airway obstruction. Administering intravenous fluids is not recommended during a seizure. Performing mouth-to-mouth resuscitation is also not indicated as the child will resume breathing spontaneously after the seizure stops. Ensuring the child's safety and preventing injury by removing harmful objects and cushioning their head is essential until the seizure subsides.

4. What is the recommended treatment for a child with a first-degree burn?

A. Immediate application of ice
B. Administration of oral antibiotics
C. Application of cool, moist compresses
D. Application of hot packs

Correct answer: C

Rationale: The recommended treatment for a child with a first-degree burn is the application of cool, moist compresses. This helps in reducing pain and swelling without causing further damage to the skin. Applying ice directly to a burn can lead to frostbite and worsen the injury (Choice A). Oral antibiotics are not necessary for first-degree burns as they do not typically involve infection (Choice B). Hot packs should be avoided as they can further damage the skin and increase inflammation (Choice D).

5. What is a common sign of a urinary tract infection (UTI) in toddlers?

A. Excessive thirst
B. Frequent, painful urination
C. Increased appetite
D. Skin rash

Correct answer: B

Rationale: Frequent, painful urination is a common sign of a urinary tract infection in toddlers. This symptom is often accompanied by possible fever and irritability. Excessive thirst (Choice A) is not a typical sign of a UTI in toddlers and is more commonly associated with conditions like diabetes. Increased appetite (Choice C) is not a typical symptom of a UTI in toddlers either. Skin rash (Choice D) is not a common sign of a UTI but may indicate other conditions like allergies or infections.