Scientific Method and Experimentation

The Scientific Method

• The scientific method is a step-by-step process used to answer questions and solve problems in science.
• It is based on observation, asking questions, and testing hypotheses through experimentation.

Aim

• The aim is the purpose or reason for conducting an experiment.
• It should be concise, without a predicted result, and contain an independent and dependent variable.
• The aim starts with keywords like "to investigate", "to test", "to measure", etc.
• Example: "To investigate the effect of the concentration of sucrose on the rate of cellular respiration in yeast cells."

Independent and Dependent Variables

• Independent variable: the variable being tested or measured, which affects the outcome of the experiment.
• Dependent variable: the variable being measured, which has an unknown outcome.
• In the example, the concentration of sucrose is the independent variable, and the rate of cellular respiration is the dependent variable.

Hypothesis

• A hypothesis is a statement that predicts the outcome of an experiment.
• It is based on previous research and knowledge.
• At the high school level, a hypothesis is not always necessarily true or provable.
• A hypothesis must include the independent and dependent variables and be written in the future tense.
• Example: "As the concentration of sucrose increases, the rate of cellular respiration in yeast cells will also increase."

Method and Materials

• Method and materials describe the steps taken to carry out the experiment.
• They should be specific, detailed, and include exact measurements.
• The method and materials should be written in a formal tone, without using pronouns like "I" or "we".
• Example: "Four test tubes, each with a different concentration of sucrose, were used. The same species of yeast was used, and a small amount of salt was added."

Control Experiment

• A control experiment is a part of the investigation where the independent variable is removed.
• All other variables remain the same.
• The easiest way to identify a control experiment is to remove the main player or substance that is doing the work.
• Example: The first test tube with no sucrose is the control experiment.

Validity and Reliability

• Validity refers to the accuracy of the results.
• It is achieved by keeping all variables constant, except for the independent variable.
• Reliability refers to the consistency of the results.
• It is achieved by repeating the experiment, increasing the sample size, and calculating an average.

Analyzing Results

• After conducting the experiment, results are collected and analyzed.
• The results may be presented in a table or graph.
• The results should be used to support or reject the hypothesis.### Choosing the Right Graph
• The type of data collected determines the type of graph to plot
• In this case, a line graph is chosen because it is continuous data

Writing a Conclusion

• A conclusion is a final statement confirming or disproving the hypothesis
• It must include the independent and dependent variables
• It must either support or disprove the hypothesis
• It should not contain any results or numbers
• It is a statement, not a question

Key Points for Writing a Conclusion

• Restate the hypothesis in different words
• Clearly state whether the hypothesis is supported or disproved
• Focus on the overall trend or pattern, not specific data points

Example of a Conclusion

• As sucrose increases, so does respiration rate in yeast
• This conclusion is supported by the graph, which shows an increase in volume of gas as sucrose concentration increases

The Scientific Method

• A step-by-step process used to answer questions and solve problems in science based on observation, asking questions, and testing hypotheses through experimentation.

Aim

• The purpose or reason for conducting an experiment, which should be concise, without a predicted result, and contain an independent and dependent variable.
• It should start with keywords like "to investigate", "to test", "to measure", etc.
• Example: "To investigate the effect of the concentration of sucrose on the rate of cellular respiration in yeast cells."

Independent and Dependent Variables

• Independent variable: the variable being tested or measured, which affects the outcome of the experiment.
• Dependent variable: the variable being measured, which has an unknown outcome.
• Example: In the experiment, the concentration of sucrose is the independent variable, and the rate of cellular respiration is the dependent variable.

Hypothesis

• A statement that predicts the outcome of an experiment, based on previous research and knowledge.
• Must include the independent and dependent variables and be written in the future tense.
• Example: "As the concentration of sucrose increases, the rate of cellular respiration in yeast cells will also increase."

Method and Materials

• Describe the steps taken to carry out the experiment, including specific details and exact measurements.
• Should be written in a formal tone, without using pronouns like "I" or "we".
• Example: Four test tubes, each with a different concentration of sucrose, were used.

Control Experiment

• A part of the investigation where the independent variable is removed, while all other variables remain the same.
• The easiest way to identify a control experiment is to remove the main player or substance that is doing the work.
• Example: The first test tube with no sucrose is the control experiment.

Validity and Reliability

• Validity refers to the accuracy of the results, achieved by keeping all variables constant, except for the independent variable.
• Reliability refers to the consistency of the results, achieved by repeating the experiment, increasing the sample size, and calculating an average.

Analyzing Results

• Collect and analyze results after conducting the experiment.
• Results may be presented in a table or graph.
• Results should be used to support or reject the hypothesis.

Choosing the Right Graph

• The type of data collected determines the type of graph to plot.
• In this case, a line graph is chosen because it is continuous data.

Writing a Conclusion

• A final statement confirming or disproving the hypothesis.
• Must include the independent and dependent variables.
• Must either support or disprove the hypothesis.
• Should not contain any results or numbers.
• It is a statement, not a question.

Key Points for Writing a Conclusion

• Restate the hypothesis in different words.
• Clearly state whether the hypothesis is supported or disproved.
• Focus on the overall trend or pattern, not specific data points.

Example of a Conclusion

• As sucrose increases, so does respiration rate in yeast.
• This conclusion is supported by the graph, which shows an increase in volume of gas as sucrose concentration increases.