Experiment Design on the ACT® Science Test

Introduction

The ACT® Science Test frequently includes questions about experiment design. This is a crucial topic in the Scientific Investigation (SIN) category. The test assesses your ability to understand why certain experimental procedures were chosen and how they were carried out.

Understanding Experiment Design

Experiment design questions evaluate your capacity to reason about scientific methodologies. You'll need to analyze why scientists chose specific measurement techniques, the timing of measurements, and the overall structure of the experiment. This skill is essential for interpreting scientific studies and understanding the logic behind research methods.

Types of Experiment Design Questions

The ACT® presents various question types related to experiment design. While the specific details may vary, all these questions require you to find evidence explaining the experimental procedures. Let's explore some common question types:

1. Measurement Origin

These questions ask you to determine how a specific measurement was obtained. You'll need to examine diagrams, charts, and text to identify the source of the measurement. Pay attention to what's being measured (e.g., volume, mass, electrons) and match it with the appropriate instrument or procedure mentioned in the passage.

2. Specific Experimental Details

Sometimes, the ACT® will ask about very specific aspects of an experiment, such as the color of a solution. These questions often relate to why the experiment was designed in a particular way. For instance, a clear solution might be necessary for observing color changes during a reaction. When approaching these questions, it can be helpful to scan the answer choices first to guide your search for relevant information in the passage.

3. Experimental Conditions

Questions about experimental conditions, such as why measurements were taken on specific days or under certain circumstances, are common. These questions test your ability to connect experimental procedures with the goals of the study. For example, measuring dust intake on days without rain makes sense because rain would remove dust from the air, potentially skewing the results.

Conclusion

You've seen different ways the ACT® can ask you why an experiment is done in a certain way. The application of these techniques will rely on your discretion. You need to recognize when you should consult the text first, or when to look at the answer choices. You'll have to develop the critical reasoning skills to reduce the ACT® Science questions to their basic format to understand, answer for yourself and then solve them.