OSAT OSAT Scientific Inquiry and Principles 4 — Questions and Answers
Question 1: A student measures the length of a pencil as 14.2 cm, 14.1 cm, and 14.3 cm in three trials. The actual length is 14.2 cm. These measurements are best described as:
- Accurate but not precise
- Precise but not accurate
- Both accurate and precise (Correct answer)
- Neither accurate nor precise
Correct answer: Both accurate and precise
The measurements cluster closely together (precise) and are centered on the true value (accurate), so they are both.
Question 2: Which of the following is an example of a systematic error in an experiment?
- A student accidentally records the wrong number once
- A balance that consistently reads 2 grams too heavy (Correct answer)
- A thermometer that reads correctly most of the time
- Random variation in reaction times
Correct answer: A balance that consistently reads 2 grams too heavy
Systematic errors consistently skew results in the same direction, such as a miscalibrated instrument.
Question 3: When designing an experiment, operational definitions are used to:
- Explain how variables will be measured (Correct answer)
- Select the sample size
- Identify the independent variable
- Present conclusions to other scientists
Correct answer: Explain how variables will be measured
Operational definitions specify exactly how a variable will be measured or manipulated in a study.
Question 4: A student's experiment shows that caffeine increases heart rate. To strengthen this conclusion, the student should:
- Reduce the number of test subjects
- Increase the number of trials and subjects (Correct answer)
- Remove the control group
- Change the dependent variable
Correct answer: Increase the number of trials and subjects
Increasing the number of trials and subjects reduces variability and strengthens the reliability of conclusions.
Question 5: Which SI unit is used to measure the amount of a substance?
- Gram
- Liter
- Mole (Correct answer)
- Kelvin
Correct answer: Mole
The mole (mol) is the SI base unit for the amount of substance, defined by Avogadro's number.
Question 6: Scientific models are most useful because they:
- Provide exact replicas of reality
- Allow scientists to visualize and test ideas about complex systems (Correct answer)
- Replace the need for experimentation
- Are always created using computers
Correct answer: Allow scientists to visualize and test ideas about complex systems
Scientific models simplify complex systems to help scientists visualize, predict, and test explanations.
Question 7: Which of the following practices BEST protects the integrity of scientific research?
- Selectively reporting only favorable results
- Maintaining detailed lab notebooks and transparent methods (Correct answer)
- Keeping experimental methods confidential
- Conducting experiments without hypotheses
Correct answer: Maintaining detailed lab notebooks and transparent methods
Detailed documentation and transparent methods allow others to evaluate, replicate, and build on research.
OSAT OSAT Scientific Inquiry and Principles 4
A student measures the length of a pencil as 14.2 cm, 14.1 cm, and 14.3 cm in three trials.
The actual length is 14.2 cm.
These measurements are best described as: