Larson 
El uso del método científico [PDF ebook] 
Using the Scientific Method

Expanding on our popular Let’s Explore Science series, this book focuses on the scientific method. The scientific method is a step-by-step process for solving science problems. Scientists use it every day. Explaining each of the five parts; observing and asking questions, researching your topic, forming a hypothesis and testing it, designing and conducting an experiment, and analyzing and drawing conclusions from your result are all mapped out in detail. Learn how this straightforward topic can sometimes be a little trickier than it seems! This book will allow students to generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.