ACT Science Research Summaries Comparing Experiments What Changed Between Studies 1 and 2

What This Is and Why It Matters for the ACT

Research Summaries — Comparing Experiments: What Changed Between Studies 1 and 2 appears in the Science section of the ACT. This topic is a common feature of research summaries, where you need to compare and contrast experiments to understand what changed between studies. It typically appears on every Science test and is considered an intermediate-level topic.

Key Concepts (What You Must Know)

• Experimental design: A plan for conducting experiments to answer a research question.
• Variables: Factors that can affect the outcome of an experiment.
• Control group: A group in an experiment that does not receive the treatment being tested.
• Independent variable: The factor being tested in an experiment.
• Dependent variable: The outcome being measured in an experiment.

Step-by-Step Strategy for This Topic

1. Read the question carefully: Understand what is being asked and what changed between studies.
2. Identify the variables: Determine which variables were changed between studies.
3. Compare the results: Analyze how the changes in variables affected the outcome of the experiment.
4. Eliminate incorrect answers: Use the process of elimination to rule out answer choices that do not match the information in the passage.
5. Choose the correct answer: Select the answer choice that best matches the information in the passage.
6. Verify your answer: Check your work by re-reading the passage and ensuring that your answer is supported by the text.

How It’s Tested on the ACT

The Science section of the ACT tests your ability to analyze research summaries and compare experiments. Questions may include: * Multiple-choice questions with five answer choices.
* Data representation questions that require you to analyze graphs and charts.
* Research summary questions that require you to compare and contrast experiments.

Common distractors include: * Misreading the passage: Failing to read the passage carefully and accurately.
* Misunderstanding the variables: Failing to identify the variables being tested or changed.
* Not comparing the results: Failing to analyze how the changes in variables affected the outcome of the experiment.

Common Mistakes & Exam Traps

• The mistake: Not reading the passage carefully.
• Why it happens: Misunderstanding the question or rushing through the passage.
• How to avoid it: Take your time and read the passage carefully, underlining key points and identifying the variables being tested.
• Exam board insight: The ACT penalizes students for not reading the passage carefully, so make sure to take your time and read the passage thoroughly.
• The mistake: Misunderstanding the variables.
• Why it happens: Failing to identify the variables being tested or changed.
• How to avoid it: Make sure to identify the variables being tested or changed and understand how they relate to the outcome of the experiment.
• The mistake: Not comparing the results.
• Why it happens: Failing to analyze how the changes in variables affected the outcome of the experiment.
• How to avoid it: Make sure to compare the results of the experiment and analyze how the changes in variables affected the outcome.
• The mistake: Not verifying your answer.
• Why it happens: Failing to check your work and ensure that your answer is supported by the text.
• How to avoid it: Verify your answer by re-reading the passage and ensuring that your answer is supported by the text.

Practice Questions (3-5 questions)

Question 1
Read the passage below and answer the question that follows.

Studies 1 and 2 investigated the effect of exercise on blood pressure. Study 1 involved 20 participants who exercised for 30 minutes, three times a week, for six weeks. Study 2 involved 20 participants who exercised for 60 minutes, three times a week, for six weeks.

What changed between Studies 1 and 2?

A) The duration of exercise B) The frequency of exercise C) The type of exercise D) The duration of exercise and the frequency of exercise E) The type of exercise and the duration of exercise

Answer: D) The duration of exercise and the frequency of exercise

Explanation: The passage states that Study 1 involved 30 minutes of exercise, three times a week, for six weeks, while Study 2 involved 60 minutes of exercise, three times a week, for six weeks. Therefore, the duration of exercise and the frequency of exercise changed between studies.

Question 2
Read the passage below and answer the question that follows.

A study investigated the effect of a new medication on blood pressure in patients with hypertension. The study involved 100 patients who were randomly assigned to either a treatment group or a control group. The treatment group received the new medication, while the control group received a placebo.

What changed between the treatment group and the control group?

A) The type of medication B) The dosage of medication C) The type of medication and the dosage of medication D) The type of medication and the duration of treatment E) The dosage of medication and the duration of treatment

Answer: C) The type of medication and the dosage of medication

Explanation: The passage states that the treatment group received the new medication, while the control group received a placebo. Therefore, the type of medication changed between the treatment group and the control group. Additionally, the dosage of medication also changed, as the treatment group received the new medication, while the control group received a placebo.

Question 3
Read the passage below and answer the question that follows.

Studies 1 and 2 investigated the effect of a new fertilizer on plant growth. Study 1 involved 20 plants that were fertilized with a standard fertilizer, while Study 2 involved 20 plants that were fertilized with a new, experimental fertilizer.

What changed between Studies 1 and 2?

A) The type of fertilizer B) The dosage of fertilizer C) The type of fertilizer and the dosage of fertilizer D) The type of fertilizer and the duration of treatment E) The dosage of fertilizer and the duration of treatment

Answer: A) The type of fertilizer

Explanation: The passage states that Study 1 involved a standard fertilizer, while Study 2 involved a new, experimental fertilizer. Therefore, the type of fertilizer changed between studies.

Quick Reference Card (60-Second Summary)

• Variables: Factors that can affect the outcome of an experiment.
• Control group: A group in an experiment that does not receive the treatment being tested.
• Independent variable: The factor being tested in an experiment.
• Dependent variable: The outcome being measured in an experiment.
• Experimental design: A plan for conducting experiments to answer a research question.
• Compare and contrast: Analyze how changes in variables affect the outcome of an experiment.

If You Get Stuck on Test Day

• Take your time: Don't rush through the passage or question.
• Read carefully: Make sure to read the passage and question carefully, underlining key points and identifying the variables being tested.
• Eliminate incorrect answers: Use the process of elimination to rule out answer choices that do not match the information in the passage.
• Choose the correct answer: Select the answer choice that best matches the information in the passage.
• Verify your answer: Check your work by re-reading the passage and ensuring that your answer is supported by the text.

Related ACT Topics

• Experimental design: A plan for conducting experiments to answer a research question.
• Variables: Factors that can affect the outcome of an experiment.
• Control group: A group in an experiment that does not receive the treatment being tested.
• Independent variable: The factor being tested in an experiment.
• Dependent variable: The outcome being measured in an experiment.