Practical Techniques And Basics

Question 1

How can we develop a testable hypothesis

Answer 1

Identify a question to answer and write an hypothesis using information provided and use clues

Question 2

What is a null hypothesis?

Answer 2

Opposite of your hypothesis
The idea that there will be no effect
Negative

Question 3

What is the independent variable, dependent variable and controlled variable?

Answer 3

Independent variable is what is changed, dependent variable is what is measured and observed, controlled variable that is kept constant because may affect values of dependent variables

Question 4

What unit is a buttered measured to?

Answer 4

To 0.1 cm3

Question 5

What unit should lengths be measured to?

Answer 5

Millimeters

Question 6

How can experiments be organized?

Answer 6

• Number steps
• Organize results e.g graphs, statistics
• Do a trial
• Put a tick on each instruction once completed to ensure accurate data
• Annotate
• Check that you have all apparatus

Question 7

What is one of the benefits of a colorimeter?

Answer 7

It allows reproducible results

Question 8

List the steps for a risk assessment

Answer 8

• Make sure space is organized and tidy
• Dry and wet areas
• Inform teacher in case of accidents
• Clear up spillage immediately
• Go through the hazards

Question 9

How should observations be recorded?

Answer 9

• In a table, first column should be the dependent variable, there should be no units in the body and always use (/) to separate units
• Arrange in order, use a pencil and ruler, leave space

Question 10

How should procedures be evaluated?

Answer 10

• Method and quality of data
• Confidence
• Measurement errors include systematic and random errors
• Systematic errors : common, measuring device, control variables
• Random errors: Do not carry out the same procedure each time

Question 11

What should be taken to account in terms of controlled variables?

Answer 11

Certain abiotic factors can’t be controlled

Question 12

What type of experiments produce valid results

Answer 12

Control experiments

Question 13

Define accuracy

Answer 13

How close the result is to the true value

Question 14

What is an anomaly

Answer 14

Don’t fit in the trend, differ significantly

Question 15

What is precesion?

Answer 15

Refers to spread of measurement about the mean value. Measure of closeness between individual results under same conditions

Question 16

How many times should repeatable regulars be carried out?

Answer 16

At least 3 times

Question 17

How are results accurately written?

Answer 17

Be specific about your results, could include resolution, replicates and expected trend

Question 18

What is a valid investigation?

Answer 18

Measuring what you intended to measure which means changes to IV leads to changes in DV

Question 19

What are valid results?

Answer 19

What you are out to measure