Science Method - RD

Question 1

Variables

Answer 1

Things/factors which change during an investigation

Question 2

Independent variable

Answer 2

• The variable that you choose to change
• The input variable
• The “cause”

Question 3

Dependent variable

Answer 3

• The variable that you measure
• The output variable
• The “effect”

Question 4

Fair testing and validity

Answer 4

Ensuring all other variables in an investigation are fixed so that you can fairly test the independent variable and how it affects the dependent variable.

Question 5

Fixed variables

Answer 5

All other variables that could affect the output or dependent variable are fixed or kept the same throughout the investigation.

Question 6

Accuracy

Answer 6

How close your measurement is to the true value you are trying to measure.

Question 7

Precision

Answer 7

How similar the value your measurement is each time you repeat the measurement.

Question 8

Reliable

Answer 8

How accurate and precise your measurements are.

Question 9

Ensuring reliability

Answer 9

Ensure that your measurements are accurate and precise. To do this you need to repeat the process of measuring a number of times to be able to establish accuracy and precision. Generally, you need to report using the average or mean value.

Question 10

Safety precautions

Answer 10

What could result in harm to humans or the environment? E.g. ensure lab safety rules followed. Be specific about the danger and the precaution required.

Question 11

A hypothesis

Answer 11

A testable statement in the form of an “If… then… because statement.”

Question 12

Conclusions

Answer 12

State whether the results support or do not support the hypothesis. Rewrite the hypothesis and give reasons where possible.

Question 13

Bar graph

Answer 13

Used when the independent variable is in the form of category data e.g. colour, male vs female.

Question 14

Line graph

Answer 14

Used when the independent variable is in the form of continuous data usually showing a particular change through time.

Question 15

Scatter graph

Answer 15

Used when the independent variable is in the form of continuous data. Once multiple dots are plotted, trends can be spotted and samples can be compared. Sometimes a line of best fit is drawn (e.g. straight line or curve).

Question 16

Pie graph

Answer 16

When you are representing the parts of a whole (e.g. percentages).

Question 17

General placement of variable in a graph

Answer 17

Independent on the X-axis (horizontal)

Dependent on the Y-axis (vertical)

Question 18

Working with the scale on a graph

Answer 18

• Use your ruler to draw check marks (typically every 1 cm for 10-15 cm)
• Look at the minimum and maximum values and ensure these fit onto the axis
• If not including 0 in your scale include a double line for the break in your axis

Question 19

Labelling the axes

Answer 19

Ensure you name the variable and include the unit in brackets. e.g. time (seconds)

Question 20

Suitable headings for graphs and tables

Answer 20

Must include both the dependent and independent variables in the description

Question 21

Appropriate table layout

Answer 21

• Independent variable on the left and dependent on the right.
• Column headings include the units in brackets e.g. height (m).
• No units should be used in the cells - only values.
• Tables must be drawn with a ruler such that each cell has lines drawn around them.