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 one benefit of using a large sample size in an experiment?

A. Chance variation is less likely to affect the results.
B. The possibility of a placebo effect is eliminated.
C. The experiment will be double-blind.
D. The control group will be similar to the experimental group.

Correct answer: A

Rationale: Corrected Rationale: Using a large sample size reduces the likelihood of chance variation affecting the results, providing more reliable data. Choice B is incorrect because the placebo effect is related to participants' beliefs, not sample size. Choice C is incorrect as double-blind refers to a method of reducing bias, not directly related to sample size. Choice D is incorrect because the similarity between the control and experimental groups is not solely dependent on sample size.

3. What should be assessed in a child with suspected appendicitis?

A. Level of consciousness
B. Bowel sounds and pain location
C. Skin color and temperature
D. Heart rate and blood pressure

Correct answer: B

Rationale: The correct answer is to assess bowel sounds and pain location. In a child with suspected appendicitis, focusing on bowel sounds and pain location, particularly in the lower right quadrant, is crucial. This assessment helps to identify symptoms commonly associated with appendicitis. Assessing the level of consciousness (Choice A) is important in other conditions such as head injuries or neurological issues. Skin color and temperature (Choice C) are more indicative of circulatory or skin-related problems. Heart rate and blood pressure (Choice D) are vital signs that are essential to assess in various conditions but are not specific to suspected appendicitis.

4. What is a common complication of uncontrolled type 1 diabetes in children?

A. Hyperactivity
B. Ketoacidosis
C. Hypertension
D. Hypoglycemia

Correct answer: B

Rationale: Ketoacidosis is a prevalent complication of uncontrolled type 1 diabetes in children. It is a serious condition characterized by high levels of ketones in the blood, leading to acidosis. Prompt medical attention is necessary to manage this potentially life-threatening condition. Choice A, hyperactivity, is not a typical complication of uncontrolled type 1 diabetes. Choice C, hypertension, is not a direct complication of type 1 diabetes in children. Choice D, hypoglycemia, is more commonly associated with low blood sugar levels, which can occur due to excessive insulin administration or inadequate food intake in diabetic individuals, rather than uncontrolled type 1 diabetes.

5. By chemical analysis, what nutrient is present in the highest amounts in most foods?

A. fats
B. water
C. proteins
D. carbohydrates

Correct answer: B

Rationale: The correct answer is B. Water is the most abundant nutrient in many foods. Water content varies across different foods, but in general, it is present in the highest amounts. Fats (Choice A) are essential but are not found in higher amounts compared to water. Proteins (Choice C) and carbohydrates (Choice D) are also important nutrients, but they are typically found in lower quantities in most foods compared to water.