Scientific Investigations Conducting a Scientific Experiment Scientific investigations

Scientific Investigations

Conducting a Scientific Experiment

• * Scientific investigations are objective, systematic approaches to answering questions about the natural world. • *The goal is to better understand how nature works by modeling this behavior as laws and theories. • *There are several processes involved in conducting a scientific investigation.

• *A hypothesis is an informed conjecture about how nature works, testable, but not yet tested and confirmed. • * A hypothesis is more than a prediction because a hypothesis proposes a law, model, or theory that supports predictions and relates them to other variables. • *Hypothesis are valuable even if they are not supported by data. They often lead to further investigations.

• *A variable is any measurable property of a natural system that can change in response to other variables. • * Observation is the process of obtaining information by using the senses and by using instruments designed for the purpose. • * It can also mean the record of an event or a measurement of a variable.

• * Processes used in scientific investigations include: • • • 1. Defining a problem or a question. 2. Planning a strategy for the investigation. 3. Identifying variables that could be important. 4. Collecting data and information. 5. Organizing data.

• 6. Analyzing and interpreting data. • 7. Making predictions from the data. • 8. Testing those predictions.

• * Of course scientific investigations require use of appropriate and reliable equipment and technology. • * Scientific investigations do not always use these exact steps in this order. • * The strategy used must be intelligently adapted to each particular situation.

Types Of Scientific Investigations

• * Ideally an experiment is a systematic procedure to study something under controlled and regulated conditions. • * But in some types of investigations, like fieldwork, or observations of unexpected events, scientists must “make do” by dealing with uncontrolled conditions.

• * Laboratory experiments allow scientists to make precise observations because they are able to control more factors. • * Other types of investigations involve many more variables. • * On the other hand, other scientific investigations may do a better job of replicating the exact conditions of nature.

Characteristics of Good Scientific Investigations

• * The quality of scientific investigations can be judged in a number of ways. • * Good investigations are • • 1. Carefully planned. 2. Well controlled. 3. Have a large sample size. 4. The procedure and results are clearly documented so that the experiment may be critiqued by peers and replicated by others.

• * Scientific results reported in newspapers, magazines, or on the internet should, ideally, posses these qualities. • * Often they do not, due to careless reporting, or misguided attempt to simplify a complex subject. • * Such imperfect accounts make it difficult or impossible for the reader to judge the quality of the science reported.