Unit 1 - AOS1 - Key science skills and terminology

Question 1

Precision

Answer 1

Results are closely grouped together

How to increase?
- Reduce random errors
- Refine measuring process (equipment)

Question 2

Which is precise which is not?
1.
- 2.1mL
- 105.0mL
- 7.3 mL
- 29.9 mL

2. • 2.1mL
   • 2.05mL
   • 2.0mL
   • 1.9mL

Answer 2

1. = Not precise results
2. = Precise results

Question 3

Accuracy

Answer 3

How close your results are to the true value (repeats do not improve accuracy)

Question 4

Which is accurate and which is not?
1. True value = 2.0mL
- 2.1mL
- 2.0mL
- 1.9mL

2. True Value = 2.0mL
   - 7.3mL
   - 105.0mL
   - 29.9mL

Answer 4

1. = Accurate results
2. = Not accurate results

Question 5

Types of errors?

Answer 5

• Systemic = if the equipment is not measuring accurately
• Personal = Cause by mistakes made by your or your research team
• Random = are unpredictable and could be due to natural variation in nature

Question 6

Reliability

Answer 6

Degree of consistency or repeatability of a measure

Question 7

Repeatable and reproducible (in terms of reliability)

Answer 7

• Repeatable = repeat the method and get the same results
• Reproducible = someone else repeats experiment and gets the same results

Question 8

Validity

Answer 8

Does the experiment answer the research question?

Question 9

Outliers

Answer 9

A data point that differs significantly from other data points

Question 10

The 2 types of observation

Answer 10

• Qualitative
• Quantitative

Question 11

Qualitative Observations

Answer 11

Involve how things appear to your senses.
e.g. shape, colour, hardness, roughness, sweetness etc.

Question 12

Quantitative Observations

Answer 12

Involve counting or measuring the quantity of something
e.g. How many?, How much?

Question 13

Independent variable

Answer 13

‘ I change on purpose ‘
- What is changed/ different

Question 14

Dependant variable

Answer 14

‘ I am data’
- what is being measured

Question 15

Control variable

Answer 15

‘Control=stays the same ‘

Question 16

What is a solution?

Answer 16

A mixture where one substance dissolves in another

Question 17

Solute

Answer 17

Dissolved parts of a solution