IB Biology Skills: Reliability 3

This video tutorial covers IB biology skills focusing on reliability and random errors. It explains the concept of reliability, the impact of random errors, and methods to reduce them, such as increasing trials and sample size. The video also discusses identifying and handling outliers, calculating averages, and provides sample exam questions on reliability. Key concepts include understanding random errors, their sources, and improving experimental reliability.

What is the primary difference between reliability and precision in experiments?

• Reliability refers to accuracy, while precision refers to consistency.

• Reliability is about consistency, while precision is about closeness of results.

• Reliability is about closeness of results, while precision is about accuracy.

• Reliability and precision are the same in experimental terms.

Which of the following is NOT a source of random error in biology experiments?

• Experimental factors

• Intrinsic variability

• Environmental conditions

• Systematic bias

How can increasing the number of trials help in reducing random errors?

• It averages out random variations.

• It decreases the sample size.

• It increases the likelihood of systematic errors.

• It eliminates all errors completely.

In the context of the video, what does increasing the sample size achieve?

• It decreases the reliability of the experiment.

• It reduces the number of trials needed.

• It increases the variability of results.

• It enhances the reliability of the experiment.

Why is it important to remove outliers from experimental data?

• Outliers are always the most accurate data points.

• Outliers always indicate a mistake in the experiment.

• Outliers should be included to increase sample size.

• Outliers can skew the results and affect reliability.

What is the effect of including outliers when calculating the average?

• It always improves the reliability of the average.

• It can distort the average, making it unreliable.

• It has no effect on the average.

• It makes the average more accurate.

Which method is NOT used to improve the reliability of an experiment?

• Changing the hypothesis

• Repeating the experiment

• Removing outliers

• Calculating the average

What is a positive control in an experiment?

• A control that produces an unknown response

• A control that is always unreliable

• A control that produces a known response

• A control that is not used in experiments

Why is it important to use the same method and equipment in repeated trials?

• To reduce the number of trials needed

• To ensure the experiment is faster

• To maintain consistency and reliability

• To increase the number of variables

What should be done if an outlier is identified in the data?

• Include it in the average calculation

• Ignore it completely

• Investigate the cause and decide if it should be excluded

• Always consider it as the most accurate data point