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. What is a common sign of dehydration in a child with diarrhea?

A. Decreased urine output
B. Increased appetite
C. Warm, dry skin
D. Elevated blood pressure

Correct answer: A

Rationale: The correct answer is A: Decreased urine output. When a child with diarrhea is dehydrated, they may have decreased urine output, indicating that their body is conserving fluids. This sign highlights the importance of fluid replacement to prevent worsening dehydration. Choices B, C, and D are incorrect. Increased appetite is not typically associated with dehydration but can be seen in other conditions. Warm, dry skin may be a sign of fever or other skin conditions, not specifically dehydration. Elevated blood pressure is not a common sign of dehydration in a child with diarrhea.

3. Which individual is making a food choice based on negative association?

A. A tourist from China who rejects a hamburger due to unfamiliarity
B. A child who spits out his mashed potatoes because they taste too salty
C. A teenager who grudgingly accepts an offer for an ice cream cone to avoid offending a close friend
D. An elderly gentleman who refuses a peanut butter and jelly sandwich because he considers it a child's food

Correct answer: D

Rationale: Choice D is the correct answer because the elderly gentleman is refusing the peanut butter and jelly sandwich due to his negative association of considering it a child's food. This negative association influences his food choice. Choices A, B, and C do not involve negative associations with the food being consumed. Choice A is based on unfamiliarity, Choice B is due to taste preference, and Choice C is driven by social considerations rather than negative food association.

4. What is the primary goal in managing a child with chronic asthma?

A. Achieve and maintain symptom control
B. Avoid all physical activity
C. Increase dietary sodium
D. Restrict medication use

Correct answer: A

Rationale: The primary goal in managing a child with chronic asthma is to achieve and maintain symptom control. This helps improve the child's quality of life by reducing asthma symptoms and exacerbations. Choice B is incorrect because avoiding all physical activity is not recommended for children with asthma; in fact, regular physical activity can be beneficial. Choice C is incorrect as increasing dietary sodium is not a primary goal in managing asthma. Choice D is incorrect because restricting medication use can lead to uncontrolled asthma symptoms and complications.

5. What is the priority assessment for a child with suspected appendicitis?

A. Temperature
B. Heart rate
C. Respiratory rate
D. Pain level

Correct answer: D

Rationale: The priority assessment for a child with suspected appendicitis is 'Pain level.' Evaluating the pain level, particularly in the lower right quadrant, is crucial as it helps in determining the severity of the condition, leading to prompt diagnosis and treatment. Monitoring temperature, heart rate, and respiratory rate are important aspects of assessment; however, they are secondary to assessing the pain level in cases of suspected appendicitis. Pain assessment is key in diagnosing this condition since the classic presentation includes abdominal pain that often starts around the umbilicus and then localizes to the right lower quadrant.