Using a Scientific Approach

Scientific Methods The scientific method is an organized plan for gathering, organizing, and communicating information. The goal of any scientific method is to solve a problem or to better understand an observed event. Scientific investigations often begin with an observation.

Our Laboratory Format Purpose Hypothesis Procedure Data and Observations Analysis Conclusion Follow-up

Purpose The reason for doing an experiment. The purpose can be: The reason for doing an experiment. A statement describing what the scientist is trying to learn more about. A question that a scientist is trying to answer.

Hypothesis The hypothesis is a proposed answer to a question or your best educated guess. It is usually stated in an “If…, then…” format. For Example: If the heat of chili sauce is related to number of chili peppers, then the more chili peppers the hotter the chili.

Procedure The procedure is set of steps to follow to conduct the actual experiment. Steps should be written in numbered sequence and be very precise. Anyone should be able to read your procedures and perform the same experiment you are running.

Data and Observations Data is a collection of facts/observations/measurements/etc… produced by an experiment. Observations are details/descriptions measured by our senses and tools . These are most often given in a data table.

Format of a Data Table Always use rulers for straight lines!!! Tables should be numbered and titled. Table 1. Effect of size of beaker on burn time Size of Beaker (ml) Time (Sec. )

Two Types of Observations Quantitative: Observations that involve number values. The cube is 3 meters in length Qualitative: Observations that DO NOT involve number values. The cube is black

Analysis Here you will analyze the data you have collected. There will usually be a set of questions you answer that relate to your experiment. This is also where your data may be translated into a graph.

Conclusion This section is written in paragraph form. A conclusion needs to refer back to the purpose and answer the original question. The conclusion should also state if the hypothesis was correct and provide data to explain why or why not. Personal pronouns should NOT be used in the conclusion.

General Format for a Conclusion Restate the purpose question Restate the hypothesis State whether or not the hypothesis is supported by the data you collected. Explain the analysis of data and important information gathered in the experiment. End with a summative statement.

Follow-Up The follow up is where you discuss any experimental errors (errors in the experiment, not human errors) For example: problems with materials or errors in the procedure. Also, anything that could be done differently next time or another experiment to perform.

Necessary Components of an Experiment A controlled experiment is an experiment in which only one variable, the manipulated variable, is deliberately changed at a time. A variable is any factor that can be changed in an experiment.

Important Variables Manipulated variable the variable that causes a change in another variable. Also known as the independent variable. Responding variable a variable that changes in response to a change in the manipulated variable. Also known as the dependent variable. Controlled variable Factor(s) in an experiment left unchanged. The purpose is to keep the experiment controlled.

Important Groups Experimental Group: The group or subject on which the experimental variable is tested. Control Group: The group or subject that serves as a comparison to the experimental group.