Scientific Method

What is Science?

Observation, identification, description, and explanation of phenomena (occurrences in the world around us)

Latin root for the word science is scientia meaning knowledge

Through study of science Ask Questions Develop Hypothesis (educated guesses) Design and Carry out Experiments Gain a Better Understanding of the Universe

Scientific Method

Procedure for studying natureConsists of several steps

Make an observation Ask questions Form the hypothesis Set up an experiment Collect the data Draw a conclusion Make a prediction

Making Observations and Defining the Problem

Observations are made by using the five senses (sight, touch, smell, sound, and taste) to obtain information

Making observations may lead to identifying problems

Asking Questions

By asking questions we can search for logical explanations of what we observe and find ways to solve problems

Sample Experiment

Asked to observe marine snail behavior in an aquarium

Tank contains several snails at one end and a mussel (food) at the other end

Observe snails climbing the aquarium and swarming all over the food

What is the problem?

Forming the Hypothesis

After observing and asking questions we can form an opinion about how or why something happens

Hypothesis – statement that gives the best possible response to the question Based on already known facts Educated Guess

Setting Up the Experiment

Should give accurate and measureable results

Should be designed to collect informationGoal is to prove or disprove a hypothesisSet up to examine only one condition

(variable) at a time to give meaningful data

Sample Experiment

Materials: Aquarium Food Seawater Graduated cylinder Snails Metric ruler

Sample Experiment

Sample Experiment

Experimental Variables

Independent Variable – factor that is changed or manipulated during an experiment in order to determine the effect of the change

Dependent Variable – the factor that the experimenter is measuring or counting Changes in response to the independent variable

Control Variable – all other factors in an experiment Things that the investigator attempts to control Goal is to keep them the same for all samples

Experimental Groups

Control Group Variable (Experimental) Groups

Collecting Data

Gathered from observations and measurements taken during an experiment

Qualitative Data – information that cannot be assigned a numerical value Usually collected using the five senses

Quantitative Data - anything that can be expressed as a number or quantified Include lengths, weights, masses, volumes, time,

anything expressed as a number

Observations must be recorded

Organizing Data

Organizing Data

Draw Conclusion

Based on dataSupport hypothesisSnails move faster in the presence of food