FORM 4: 1.5 ANALYSING SCIENTIFIC INVESTIGATIONS

HYPOTHESIS

MV increases, RV increases/decreases.

VARIABLES

i)          MANIPULATED VARIABLE   :

ii)         RESPONDING VARIABLE                      :

iii)       CONSTANT VARIABLE                           :

TABULATION OF DATA

MV (unit)	RV (unit)	other variable (unit)

GRAPH

VERTICAL AND HORIZONTAL AXES

Label each axis by writing the symbol representing the variable and its unit. For example, l (cm).

CHOICE OF SCALE

i)        Use the following ratios when choosing a scale.

§  2 cm to represent 0.1 unit/1 unit/10 units/100 units

§  2 cm to represent 0.2 unit/2 units/ 20 units

§  2 cm to represent 0.5 unit/ 5 units/ 50 units

ii)       The scale chosen should give a graph that covers more than 75% of your graph paper.

iii)     Avoid odd scales such as 2 cm to represent 3 units/6 units/7 units

PLOTTING THE POINTS

Points should be plotted as accurately as possible with a ‘×’.

DRAWING THE LINE

i)        Since the points are plotted using experimental data which have errors, they usually do not form an exact straight line.

ii)       The best straight line needs to be drawn.

iii)     The points not on the line should be as near as possible to the line.

iv)     The number of points above the line is approximately equal to the number points below the line.

v)      Students are advised to not connecting all the points as it will produce line that is not smooth.

ANALYSING THE GRAPH